Net-Zero and Energy-Efficient Multi-Unit Housing in Nova Scotia: What a Parcel Can Support

Low-carbon, energy-efficient housing is no longer a niche aspiration in Nova Scotia — it is increasingly the baseline the building code requires and a measurable input to how purpose-built rental gets financed. For a landowner weighing what to do with a serviced lot in the Halifax Regional Municipality (HRM), the relevant question is not "how do I build a green home?" but "what is the most this parcel can support, and how do energy performance, zoning, and financing interact to make that buildable?"

Helio Urban Development is a computation-driven real estate development company in Halifax. We compute the optimal development a parcel can support — its permitted unit yield, built form, and the economics that follow — and develop it end-to-end on land our clients own, with construction delivered by established builders. This guide takes the development-firm view: what the rules actually require on energy performance, where the real incentives sit in 2026, and how a deep-energy design changes the feasibility math rather than just the utility bill.

The energy code is rising on a fixed schedule

The first thing that has changed is the floor. Nova Scotia's building regulation now adopts the National Building Code of Canada 2020, the National Energy Code of Canada for Buildings 2020, and the National Plumbing Code of Canada 2020, in force April 1, 2025 under N.S. Reg. 198/2024 [1].

Crucially, the province is phasing in the tiered energy requirements on a published timetable. Building-code Tier 1 and energy-code Tier 1 took effect April 1, 2025; building-code Tier 2 takes effect April 1, 2026; energy-code Tier 2 follows April 1, 2027; and the higher tiers continue through 2029 [1]. For houses and small buildings, this means the energy-efficiency provisions of Section 9.36 now require at least Tier 2 performance (for climatic Zone 6, which covers HRM) as of April 1, 2026, having phased in from Tier 1 in 2025 [1].

The practical implication for a developer: "energy efficient" is a moving target written into law, and a building permitted today must meet a higher standard than one permitted last year. Designing only to the minimum is designing to a number that is scheduled to rise. A net-zero or net-zero-ready envelope is, in part, a hedge against a code that is climbing toward it anyway.

A second floor matters too. Whether a project follows the simpler Part 9 ("Housing and Small Buildings") path or the more involved Part 3 path depends on size: Part 9 applies only to buildings of 3 storeys or fewer with a building area of 600 m² or less that are not an excluded major occupancy; exceed either threshold and the project becomes a Part 3 building [2]. That distinction shapes the engineering scope, the design budget, and the energy-modelling approach long before a panel goes up — which is exactly why it belongs in a feasibility study, not a change order.

How much housing a parcel can hold

Energy performance is only worth modelling once you know how many units the land can legally carry. In HRM, that ceiling moved sharply in 2024.

Under the municipality's Housing Accelerator Fund (HAF) planning amendments — effective June 13, 2024, the date HRM received provincial approval — a minimum of four dwelling units is now permitted as-of-right on every centrally serviced residential lot, achieved by amending the low-density R-1 and R-2 zones outside the Regional Centre [3][4]. Inside the Regional Centre, the established residential zones were rebuilt: the post-HAF ER-3 zone permits up to eight dwelling units per lot (lot-size dependent), including four-unit dwellings, low-rise multi-unit buildings of five to eight units, and townhouses [5].

These thresholds are the starting point of any energy strategy, because the per-unit economics of a deep-energy design improve with scale and with shared building elements. A multi-unit building enjoys a structural energy advantage a detached house cannot: party walls between units mean less exterior surface area exposed per dwelling, which directly reduces heat loss. The four-to-eight-unit forms that HAF unlocked are well matched to that physics.

A development firm's job here is to establish the honest as-of-right number first. As-of-right development complies with all Land Use By-law requirements and can proceed by development permit without discretionary approval; a variance is a minor relaxation granted by a development officer, while larger departures require a development agreement or rezoning approved by Council [6]. Permitted unit yield in zones like ER-3 scales with lot area — the minimum lot area for one-to-four-unit dwellings is 325 m², with townhouse units requiring less area each [7]. There is no single municipality-wide minimum lot size; it is zone-specific [8]. Computing the real envelope a specific parcel allows — rather than assuming a generic figure — is the difference between a design that gets permitted and one that gets sent back.

Designing for performance: envelope first, systems second

Once the unit count is established, the energy approach follows a well-understood order of operations. The envelope comes first because it is the only part of the building you cannot easily upgrade after occupancy.

• Airtightness and continuous insulation. Continuous exterior insulation reduces thermal bridging, and a continuous air barrier limits the uncontrolled air leakage that drives heating load in a Zone 6 climate.
• High-performance glazing. Triple-pane windows with appropriate coatings reduce heat loss and drafts while preserving daylight — a meaningful contributor to envelope performance in a cold climate.
• Heat recovery ventilation (HRV). As the envelope tightens, mechanical ventilation becomes essential; an HRV reclaims heat from outgoing air to temper incoming fresh air, maintaining indoor air quality without throwing away the heat the envelope worked to keep.
• Compact form and orientation. A simpler building shape with less exterior surface area loses less heat, and orienting the long axis to optimize solar exposure improves passive performance — choices that cost little at the design stage and are impossible to retrofit.

Only after the envelope is settled do the active systems earn their place. Cold-climate (ductless) heat pumps are the workhorse for Nova Scotia heating and cooling, and a tight, well-insulated building lets them be sized smaller. Solar generation, paired with the provincial net-metering framework, can offset a share of annual consumption; battery storage can smooth supply. The barrier-free requirements of the code apply regardless of the energy strategy — at least one entrance must be barrier-free, with a barrier-free path of travel on the entrance level and in storeys served by an elevator [9] — so accessibility and energy design have to be coordinated, not bolted on.

A note on costs, in our own voice: Helio does not publish a price per unit or per square foot. For an order-of-magnitude reference, CMHC's Housing Design Catalogue (Halifax basis, Q1 2025) estimates hard construction cost for small multi-unit buildings at roughly $217,000–$387,000 per unit, depending on building type [10]. That figure is hard cost only — it includes the general contractor's overhead and profit but excludes land, financing, soft costs, and developer profit, and CMHC advises adding a 5–10% contingency [10]. A deep-energy envelope sits inside that envelope of cost; the financing tools below are what make it pencil.

Financing that rewards energy performance

This is where the development-firm view diverges most sharply from a generic "go green" pitch. In 2026, energy performance is not just a virtue — it is a lever on the capital stack.

CMHC MLI Select is CMHC's multi-unit mortgage loan insurance product, which awards points across three categories — affordability, accessibility, and climate compatibility (energy efficiency) — to unlock reduced premiums, higher leverage, and longer amortization [11]. Climate-compatibility points are earned by achieving percentage reductions in energy use and greenhouse-gas emissions over baseline building-code performance [12] — precisely what a net-zero-ready design delivers. MLI Select projects require a minimum of five units, with non-residential space capped at 30% of gross floor area [13].

The thresholds are concrete. At 50 points a project can reach up to 95% loan-to-cost on new construction with up to 40-year amortization; 70 points enables higher leverage on existing properties with up to 45-year amortization; and 100 points unlocks up to 50-year amortization [14]. Under CMHC's updated premium-discount schedule effective July 14, 2025, 50 points earns a 10% premium discount, 70 points earns 20%, and 100 points earns 30% [15] (as of 2026-06-23). For a purpose-built rental, the energy points that a deep-energy design earns can be the marginal contribution that pushes a project over a threshold — turning envelope investment into financing terms.

The Apartment Construction Loan Program (ACLP) — the renamed Rental Construction Financing initiative — is a distinct instrument: a $55-billion federal program offering fully repayable low-interest construction loans for purpose-built rental, with its timeline extended through 2031–32 under Budget 2024 [16][17]. Under the standard stream, loans start at $1 million, can cover up to 100% loan-to-cost for the residential component, carry a fixed rate locked at first advance, and allow up to 50-year amortization for projects of at least five units [18]. ACLP and MLI Select are different things — a construction loan versus mortgage loan insurance — and can be used together [19].

Tax treatment rewards new rental too. The federal Purpose-Built Rental Housing (PBRH) rebate refunds 100% of the GST (the 5% federal part of HST) on qualifying new purpose-built rental, up to $35,000 per unit with no phase-out [20], and Nova Scotia mirrors it with a 100% rebate of the 9% provincial part of HST [21]. Eligible new purpose-built rental buildings also qualify for an accelerated Capital Cost Allowance rate of 10% (instead of the usual 4% Class 1 rate) where construction begins on or after April 16, 2024 and before 2031 [22]. (Long-term residential rent itself is GST/HST-exempt, which means the landlord cannot claim input tax credits on operating inputs [23] — a structural feature worth modelling, not a surprise at year-end.) Nova Scotia's HST rate is 14% as of 2026-06-23, reduced from 15% effective April 1, 2025 [24].

The incentive landscape has narrowed — design to what is open

A great deal of older "net-zero in Nova Scotia" advice points to programs that have since closed. An honest development brief uses only what is live as of 2026-06-23:

• Efficiency Nova Scotia's SolarHomes rebate is closed to new residential applications (it stopped accepting homeowner applications April 17, 2025; approved projects had to be completed by March 31, 2026) [25].
• The Canada Greener Homes Grant is closed — in Nova Scotia the post-retrofit EnerGuide deadline was November 30, 2025 and final document submission December 31, 2025; no new participants are accepted [26].
• The Nova Scotia Secondary and Backyard Suite Incentive Program has ended, with the province redirecting funding toward rent supplements [27]. Do not build a pro forma around it.
• The federal Canada Secondary Suite Loan Program (the proposed $80,000 loan) was announced but never became operational and has been reported as not proceeding [28].

What is open and relevant to multi-unit rental:

• Efficiency Nova Scotia's Commercial New Construction program offers a modeling incentive of up to $15,000 toward consultant fees plus an implementation incentive of roughly $0.13–$0.18 per kWh of verified electricity savings, for new commercial/institutional/multi-unit-residential projects of at least 15,000 ft² in the pre-construction design phase [29] (as of 2026-06-23). For a multi-unit building of meaningful size, this is the program that directly subsidizes the energy modelling MLI Select will require anyway.
• Efficiency Nova Scotia's Affordable Multifamily Housing / Affordable Housing Energy Program is open and covers a high share of eligible costs (reported up to ~$150,000 and up to 80–100% of eligible costs) for energy-efficiency upgrades to affordable multifamily rental, co-op, and non-profit properties [30].
• The Nova Scotia Affordable Housing Development Program (AHDP) provides forgivable loans to private and community developers to build new affordable rental, funding up to 50% of units in a project (up to 100% of units for projects with fewer than 10 units) [31] — a meaningful stacking partner where affordability commitments are on the table, including the affordability points MLI Select rewards (rents at or below 30% of median renter income, minimum 10-year commitment) [32].

Sequencing matters: the Commercial New Construction modeling incentive and MLI Select both want the energy model produced in the pre-construction design phase, which is the same window in which feasibility is decided. The incentives reward early planning because the building physics rewards early planning.

Two costs to plan around: the RDC and the rising code

Beyond construction, two municipal and regulatory line items belong in any HRM multi-unit feasibility model. Halifax Water's Regional Development Charge is $5,405.81 per unit for a multiple-unit dwelling and $8,048.66 per unit for a single-unit dwelling or townhouse, effective April 1, 2024 and currently frozen at 2023 levels, though increases are under engagement [33]. HRM building permit fees for new residential of four units or fewer are charged per square metre of floor area ($4.04/m² at or above grade, with lower rates below grade), with a $31.25 minimum [34]. These are modest relative to construction cost, but they are real and they are knowable in advance — which is the point of computing them rather than estimating them.

The rising code is the other planning input. Because the energy-code tiers climb on a fixed schedule through 2029 [1], a building designed to clear today's Tier 2 with margin is less likely to be obsolete on day one — and is better positioned for the climate points that turn into financing terms.

Why this is a development question, not a construction question

The temptation in net-zero conversations is to jump straight to systems — which heat pump, how many solar panels. The development-firm view inverts that. The energy strategy is downstream of two prior questions: how many units the parcel can legally support, and how the capital stack (MLI Select climate points, ACLP, the PBRH rebates, accelerated CCA, the open Efficiency Nova Scotia and AHDP programs) responds to performance. Get those right and the envelope decisions follow logically; get them wrong and even a beautifully insulated building can be financed badly.

Building energy-efficient, low-carbon rental housing in HRM aligns with Nova Scotia's legislated goal of net-zero greenhouse-gas emissions by 2050 under the Environmental Goals and Climate Change Reduction Act [35]. It also aligns, increasingly, with the building code, the financing market, and the tax treatment. The work is to compute how those forces interact on a specific parcel — and to develop accordingly.

Frequently asked questions

Is "net-zero" required by the Nova Scotia building code? No. The code does not require net-zero, but it does require rising tiers of energy performance on a published schedule — at least Tier 2 of Section 9.36 for houses and small buildings in HRM's climate zone as of April 1, 2026, climbing through 2029 [1]. A net-zero-ready design is a way to stay ahead of a standard that is moving toward higher efficiency anyway.

How does energy efficiency affect financing for a rental building? Through CMHC MLI Select, energy-use and greenhouse-gas reductions over baseline code performance earn climate-compatibility points [12]. Reaching the 50-, 70-, and 100-point thresholds unlocks higher leverage, longer amortization, and premium discounts of 10–30% (effective July 14, 2025) [14][15]. For a purpose-built rental of at least five units, the energy investment can directly improve financing terms.

Which Nova Scotia incentives are still open in 2026 for an energy-efficient multi-unit build? As of 2026-06-23: Efficiency Nova Scotia's Commercial New Construction program (modeling incentive up to $15,000 plus a per-kWh implementation incentive) [29], the Affordable Multifamily Housing energy program [30], and the provincial Affordable Housing Development Program for affordable units [31]. The SolarHomes rebate, the Canada Greener Homes Grant, and the provincial backyard-suite program have all closed [25][26][27].

How many units can I build on a serviced HRM lot? At least four dwelling units are now permitted as-of-right on centrally serviced residential lots under the June 2024 HAF amendments [3][4], and the Regional Centre's ER-3 zone permits up to eight units per lot, lot-size dependent [5]. The exact number for a specific parcel depends on its zone and lot area — which is the first thing a feasibility study computes.

Sources

1. Government of Nova Scotia — "Province to Adopt 2020 National Building Codes" (Sept 20, 2024). https://news.novascotia.ca/en/2024/09/20/province-adopt-2020-national-building-codes
2. National Research Council Canada — Illustrated User's Guide, NBC 2020 Part 9 (Division B). https://nrc.canada.ca/en/certifications-evaluations-standards/codes-canada/codes-canada-publications/illustrated-users-guide-national-building-code-canada-2020-part-9-division-b-housing-small-buildings
3. Halifax Regional Municipality — Recent changes to planning documents for housing (HAF). https://www.halifax.ca/about-halifax/regional-community-planning/housing-accelerator-fund/urgent-changes-planning-0
4. Halifax Regional Municipality — Housing Accelerator Fund (HAF) program page. https://www.halifax.ca/about-halifax/regional-community-planning/housing-accelerator-fund
5. HRM — HAF Amendments: Permitted Uses, Regional Centre Established Residential Zones / ER Zones Fact Sheet (June 2024). https://cdn.halifax.ca/sites/default/files/documents/about-the-city/regional-community-planning/er-zones-fact-sheet-june-2024.pdf
6. Halifax Regional Municipality Charter (Nova Scotia). https://nslegislature.ca/sites/default/files/legc/statutes/halifax%20regional%20municipality%20charter.pdf
7. HRM — ER Zones Fact Sheet (June 2024) / Regional Centre Land Use By-law. https://cdn.halifax.ca/sites/default/files/documents/about-the-city/regional-community-planning/er-zones-fact-sheet-june-2024.pdf
8. HRM — Community Plan Areas / Land Use By-laws. https://www.halifax.ca/about-halifax/regional-community-planning/community-plan-areas
9. Halifax Regional Municipality — Accessible / Barrier-Free Entrance Design Guidelines (per National Building Code Section 3.8). https://cdn.halifax.ca/sites/default/files/documents/home-property/building-renovating/2024.01-barrier-free-entrance-guidelines-v1.03.pdf
10. CMHC — Housing Design Catalogue, Construction Cost Estimate Summary (Atlantic). https://assets.cmhc-schl.gc.ca/sites/housing%20catalog/resources/hdc-construction-cost-estimate-summary-atlantic-en.pdf
11. CMHC — MLI Select. https://www.cmhc-schl.gc.ca/professionals/project-funding-and-mortgage-financing/mortgage-loan-insurance/multi-unit-insurance/mliselect
12. CMHC — MLI Select (energy efficiency / climate compatibility criterion). https://www.cmhc-schl.gc.ca/professionals/project-funding-and-mortgage-financing/mortgage-loan-insurance/multi-unit-insurance/mliselect
13. CMHC — MLI Select (minimum units / non-residential cap). https://www.cmhc-schl.gc.ca/professionals/project-funding-and-mortgage-financing/mortgage-loan-insurance/multi-unit-insurance/mliselect
14. CMHC — MLI Select program PDF. https://assets.cmhc-schl.gc.ca/sites/cmhc/professional/project-funding-and-mortgage-financing/mortgage-loan-insurance/multi-unit-insurance/mliselect/mli-select.pdf
15. CMHC — Notice: CMHC to Update Multi-Unit Mortgage Loan Insurance Premiums (effective July 14, 2025). https://www.cmhc-schl.gc.ca/media-newsroom/notices/2025/cmhc-to-update-multi-unit-mortgage-loan-insurance-premiums
16. CMHC — Apartment Construction Loan Program. https://www.cmhc-schl.gc.ca/professionals/project-funding-and-mortgage-financing/funding-programs/all-funding-programs/apartment-construction-loan-program
17. CMHC — Enhancements to the Affordable Housing Fund and Apartment Construction Loan Program. https://www.cmhc-schl.gc.ca/media-newsroom/news-releases/2024/enhancements-affordable-housing-fund-apartment-construction-loan-program
18. CMHC — ACLP: Standard Rental Housing. https://www.cmhc-schl.gc.ca/professionals/project-funding-and-mortgage-financing/funding-programs/all-funding-programs/apartment-construction-loan-program/standard-rental-housing
19. CMHC — Mortgage Loan Insurance for Multi-Unit and Rental Housing. https://www.cmhc-schl.gc.ca/professionals/project-funding-and-mortgage-financing/mortgage-loan-insurance/multi-unit-insurance
20. Canada Revenue Agency — GST/HST Purpose-Built Rental Housing (PBRH) Rebate. https://www.canada.ca/en/revenue-agency/services/tax/businesses/topics/gst-hst-businesses/gst-hst-rebates/purpose-built-rental-housing.html
21. Government of Nova Scotia, Department of Finance — Purpose-Built Rental Housing Rebate. https://novascotia.ca/finance/en/home/taxation/tax101/harmonizedsalestax/purpose-built-rental-housing-rebate.html
22. Budget 2024 — Tax Measures: Supplementary Information (Accelerated CCA for Purpose-Built Rental Housing). https://www.budget.canada.ca/2024/report-rapport/tm-mf-en.html
23. Excise Tax Act, RSC 1985 c. E-15, Schedule V, Part I, para 6 (Justice Laws). https://laws-lois.justice.gc.ca/eng/acts/e-15/page-120.html
24. Canada Revenue Agency — GST/HST Notice 342 (Nova Scotia HST Rate Decrease). https://www.canada.ca/en/revenue-agency/services/forms-publications/publications/notice342/nova-scotia-hst-rate-decrease-questions-answers-general-transitional-rules-personal-property-services.html
25. Efficiency Nova Scotia — SolarHomes. https://www.efficiencyns.ca/programs-rebates/solarhomes
26. Natural Resources Canada — Closed: Canada Greener Homes Grant (Nova Scotia). https://natural-resources.canada.ca/energy-efficiency/home-energy-efficiency/canada-greener-homes-initiative/closed-canada-greener-homes-grant-nova-scotia
27. Government of Nova Scotia — Secondary and Backyard Suite Incentive Program Guidelines. https://www.novascotia.ca/documents/secondary-and-backyard-suite-incentive-program-guidelines
28. Department of Finance Canada — 2024 Fall Economic Statement (secondary suites announcement). https://www.canada.ca/en/department-finance/news/2024/12/2024-fall-economic-statement-making-it-easier-for-homeowners-to-build-secondary-suites.html
29. Efficiency Nova Scotia — Commercial New Construction. https://www.efficiencyns.ca/programs-rebates/commercial-new-construction
30. Efficiency Nova Scotia — Affordable Housing Energy Programs (Affordable Multifamily Housing). https://www.efficiencyns.ca/programs-rebates/affordable-housing-energy-programs
31. Government of Nova Scotia — Affordable Housing Development Program. https://www.novascotia.ca/apply-funding-create-affordable-housing-affordable-housing-development-program
32. CMHC — MLI Select (affordability criterion). https://www.cmhc-schl.gc.ca/professionals/project-funding-and-mortgage-financing/mortgage-loan-insurance/multi-unit-insurance/mliselect
33. Halifax Water — Regional Development Charge. https://www.halifaxwater.ca/regional-development-charge
34. Halifax Regional Municipality — Permit Fees (License, Permit and Processing Fees Administrative Order #15). https://www.halifax.ca/home-property/building-development-permits/permit-fees
35. Environmental Goals and Climate Change Reduction Act (Nova Scotia). https://nslegislature.ca/sites/default/files/legc/statutes/environmental%20goals%20and%20climate%20change%20reduction.pdf