In Western Canada, most residential solar installations are retrofits, with homeowners adding photovoltaic (PV) panels to existing properties. The same is true with on-site storage solutions, which are normally added once a rooftop PV system comes online.
However, there is a growing movement to make homes solar– and storage-ready during the design phase.
This guide outlines what the process involves, why solar-readiness is becoming so popular, and key considerations builders should weigh when designing and constructing residential properties for this rapidly-growing market.
What Are Solar-Ready (and Storage-Ready) Homes?
When it comes to solar power, retrofitting panels to existing roofs represents one end of the spectrum. At the other end, there are building-integrated photovoltaics (BIPV) homes where the panels are built into roofs during the construction process.
In the middle are solar-ready homes in which future occupants have the option of adding PV panels and storage solutions – with as few hurdles as possible. In effect, these residential properties already come equipped with the requisite surface area, wall space, and conduits to accommodate solar and storage solutions at a later date.
Why Are Solar-Ready Homes Becoming More Common?
The world is rapidly going solar, with many experts predicting that PV technology will help meet 75% of global electricity demand by 2050. Designing solar-ready homes give owners the freedom and flexibility to install PV panels whenever the investment makes sense for them – based on a combination of financing, utility rates, and relevant incentives.
Moreover, solar-readiness can be folded into the home’s total cost, allowing owners to amortize these expenses over the 20 to 30 years of a standard mortgage. This indirectly lowers the price of adding PV panels and batteries in the future – due to reduced labour costs and shorter installation times.
Together, these benefits remain a key selling point – enabling builders to charge a premium for their properties. All other things being equal, solar-ready homes command higher prices and spend less time on the market compared to traditional residential properties. In addition, solar-readiness helps to future-proof construction projects as building codes and specifications evolve.
Top 5 Considerations when Designing Solar-Ready Homes
Solar-readiness is a broad topic that encompasses many different aspects of residential construction and design. But below are the five main points that should factor into your own projects
1) The Roof
First and foremost, the home must have sufficient rooftop space to accommodate PV panels in the future. Every solar installation is unique, but for a 7.2 kW system made from 18 x 400 W panels, you should budget a minimum of 400 ft.² of unobstructed space – devoid of vents, chimneys, gables, or other common obstacles.
South-facing rooftops are ideal for maximizing sun capture – with fixed-tilt pitches based on the city’s latitude. A house at 51 degrees latitude, for example, would need a 12/12 pitch for optimal solar power generation. When South-facing rooftops aren’t available, lower angles allow for better solar output. For example, East- and West-facing roofs perform well in the 1/12 to 3/12 pitch range.
Because most residential roofs host a mix of vents and chimneys, consider installing them on North-facing roofs. Alternatively, you can install these obstacles on peak edges to ensure more continuous space for future panels. Another strategy involves grouping obstructions together to minimize their impact.
The design stage is also a great time to consider the impact of nearby trees and buildings. The goal here is to minimize shading during peak solar production hours, which fall from 9 AM to 3 PM in a market like Western Canada.
With enough modifications, any roofing system can technically accommodate solar PV panels. Standing seam metal and asphalt offer the greatest flexibility (and lowest cost) for flashings, penetrations, and anchors. By contrast, roofs made from clay tiles, wood, or rubber require more intervention. And this can increase solar installation times and costs for future homeowners.
2) The Attic
Many municipalities require structural engineering reviews to verify whether existing properties can physically support a PV installation with an extra 3psf to 6psf of additional load on a standard pitched roof with traditional solar retrofits.
Fortunately, solar-ready homes can factor these considerations into their design from day one – giving builders the option of adding lateral supports and other reinforcements during the construction phase. For an exhaustive overview of what this entails, check out the Truss Plate Institute of Canada’s Solar Ready Truss Design Procedure.
3) The Conduits
The next step involves installing the conduits used to run wires that connect rooftop panels to designated wall spaces in the electrical room, which normally houses breaker boxes, inverters, and even solar batteries. During the construction phase, it’s possible to conceal these conduits behind walls for aesthetic purposes. Just make sure you pay close attention to the:
- Size of the conduits, with a minimum of 1” diameters to accommodate electrical wiring
- Material of the conduits – rigid PVC, electrical metallic tubing, and liquid-tight flexible options being the most suitable
- Ends of the conduits – many fire codes mandate capping of unused conduits until they become operational
4) The Electrical Room
Most homes come with breaker boxes, switches, and fuses used to control the larger electrical system. But for solar-ready properties, it’s also important you designate sufficient space in the electrical rooms for inverters:
- Some jurisdictions mandate at least 3’ x 3’ next to the main electrical box when using a traditional single inverter
- For a 5 kW string inverter, strive for a minimum of 22.5” x 16” x 6.5” (H x W x D) of wall space – plus ample room on all sides to facilitate passive cooling
5) The Battery (and EV-Charging)
Given the growing popularity of self-contained energy storage systems (ESS’s), it’s now considered best practice to design new homes as battery-ready. The exact building codes vary from jurisdiction to jurisdiction. But according to the latest 2021 Canadian Electrical Code (CEC) guidelines, ESS’s can no longer be installed in basements or more than 75.5 ft off the ground.
Most homeowners install storage solutions in the electrical room or garage. Either way, adding the requisite conduits and budgeting sufficient space can help drive down battery installation costs if future occupants decide to add solar storage capacity later.
The same is true of electric vehicle (EV) charging – which is another increasingly popular design choice in the larger battery-ready movement. Although the technology continues to evolve rapidly, 60 A and 240 V are the current standards for residential fast-charging. And homeowners can choose between a typical 240V plug or a dedicated EV charger.
Your Solar Company For Solar Readiness
We hope you enjoy this brief overview of solar-ready design considerations. For a more complete overview – including detailed specs and building codes for Western Canada – download our comprehensive guide below:
If you have specific questions about solar-ready, battery-ready, or net-zero homes, schedule a free consultation with our energy experts today.
EVOLVsolar is Western Canada’s leading solar company. We have one mission: to make solar energy affordable while giving back to the environment. By investing in solar power, you can save money on energy bills, upgrade the value of your property and reduce your energy output. You can expect high-quality solar panel installation, world-class workmanship, excellent customer service and the best solar technology available. Our success has established us as the go-to solar installers in BC and Saskatchewan, and one of the leading solar companies in Alberta. Experience the EVOLVsolar difference by contacting our corporate office today at 1 (844) 276-4004.