Solar Design Checklist for Multifamily & Commercial Projects

How to plan ahead for solar on your new construction project

The earlier we lock in a solar design, the better we’re positioned to make sure there’s clear space on the roof to meet your energy needs. 

Here’s a quick guide to get your project teams on the same page if you’re considering adding solar down the road. 

How does solar work for commercial projects? 

Solar panels generate electricity which flows through an inverter that converts the DC electricity into usable AC electricity for the building. That energy directly powers what’s being consumed in the building at the time. 

• If more electricity is generated than what’s being used, the excess is sent back to the grid for a credit. 
• If there is not enough solar energy to cover the facility’s energy needs, the rest will be supplemented by the grid. 

For most multifamily projects, solar is used to offset energy use in common spaces. That helps offload operational costs for building owners and can make the property more attractive if you’re selling in the future. 

Commercial Solar System Components

Solar Panels

Solar Racking

Inverter

Optimizers

Solar Monitoring

Solar Design Recommendations for Multifamily and Commercial Buildings

The biggest hurdles we have when adding solar to a commercial property is RTU placement and fire code setback from obstructions. The more open space we have to work with, the lower the solar installation costs. 

Here are some of our top design recommendations to plan ahead for solar:

• A typical system will need a 2″ EMT conduit. These can often be roughed in through existing roof penetrations.
• Inverters are typically 24”Lx36”Wx23”D. They can be roof mounted but having that open space in the electrical room is preferred. 
• Solar systems are incorporated into the main electrical service panel (MSP).  Having the building’s electrical schedule will allow us to determine the type of inverter and system size that can be integrated, based on the phase and voltage.  
• Consult your structural and electrical engineer early in order to ensure structural load and conduit integration are incorporated 
• Group rooftop infrastructure (structural, mechanical systems, vent stacks, etc.) close together and in shaded areas, or near the north of the building when possible
• Current panels are approx 4×8 (plywood size), but can vary 
• Depending on size, solar will use 500-1000 square feet. However, we can utilize any free space 4 feet clear of obstructions and eaves.
• The best time to install solar is during construction, or new roof installation.  TPO and metal roofs have more of a flexible timeline because of their longevity compared to asphalt shingles.  We cannot install on slate, Spanish tile, or similar decorative roofing material.

Benefits of Solar for Multifamily & Commercial Projects

We’ve seen an uptick in multifamily projects going solar, with an increase of 250% adoption in the last two years. Most of our multifamily solar clients choose to go solar for these benefits: 

• Offloading Operational Costs (most common)
• Points Toward Building Certifications
• Meet Local Sustainability Requirements
• ESG Marketability for Tenants and Investors

See the Full Guide to Multifamily & Commercial Solar →

Green Building Programs with Solar

Pairing building performance + solar is the most efficient way to offset energy use (and operational costs). Our building performance and solar teams work together to help you choose the building certification and design a custom solar system that meets your project goals.

Many programs offer certification points for solar. Here’s a breakdown by program:

• NGBS: On-site Renewable Energy Systems earn 2 points per kW and Contributes to the + NET ZERO ENERGY badge 
• Green Globes: Up to 30 points for on-site renewable energy 
• Enterprise Green Communities: Up to 8 points depending on the building type and percentage of total project energy consumption provided by renewable energy
• LEED: Up to 5 points for on-site renewable energy generation

Integrating a green building program early in the design process ensures all mandatory requirements are met. It also allows for maximum customization and focus on your project goals. 

Let us know as you are updating drawings, we are happy to review those with you and your project team to maximize your energy savings and solar potential!