Green Building Premium Calculator

Green building certification (BREEAM, LEED) adds a premium to construction cost but delivers ongoing value through energy savings and higher achievable rent. Green premium typically 2-8% of build cost. Energy savings usually 20-40%. Rent premium typically 3-8% for certified buildings vs comparable uncertified.

5M standard build × 5% green premium = 250k extra cost. Annual energy saving 30k + annual rent uplift on 200k base rent × 5% = 10k. Annual benefit 40k. Payback 6.3 years. For a building lasting 50+ years, the premium pays for itself many times over.

Green buildings increasingly attract better tenants. ESG-focused corporates and public sector organisations increasingly mandate green-certified office space. Building green today is tenant risk management - uncertified buildings face growing obsolescence risk as regulation and tenant preferences shift toward sustainability.

Quick example

With standard build cost of 5,000,000 and green premium of 5% (plus energy saving annual of 30,000 and rent premium of 5%), the result is 250,000.00. Change any figure and watch the output shift — it's often more useful to see the pattern than to memorise the formula.

Which inputs matter most

You enter Standard Build Cost, Green Premium %, Energy Saving Annual, Rent Premium %, and Annual Rent Base. Not every input has equal weight. Adjusting one input at a time toward extreme values shows which ones move the result most.

What's happening under the hood

Premium = build cost × green %. Annual benefit = energy savings + (rent base × rent premium %). Payback = premium ÷ annual benefit. The formula is listed in full below. If the number looks off, you can retrace the calculation by hand — that's the point of showing the working.

Cost vs value in green choices

Sustainable options usually cost more upfront and less over time. This tool separates the two so the comparison is fair — looking at purchase price alone consistently makes the green option look worse than it is once lifetime costs are tallied.

What this doesn't capture

Carbon reduction, health benefits, and local air quality have real value the financial figure doesn't price. The calculation gives the money side honestly; for the full picture, note the non-financial benefits alongside.