A sustainable fit-out without the greenwash

A practical guide to a lower-carbon office fit-out: reuse first, embodied carbon, the 2026 MEES position, and what BREEAM, NABERS UK and WELL measure.

Start with what is already there

Any credible sustainable fit-out begins with an audit of what already exists. Work through the options in this order:

1. Keep in place. Raised floors, ceiling grids, partitions, doors and light fittings that are sound and suit the new layout.
2. Refurbish. Refinish joinery, reupholster seating, recover meeting tables.
3. Reuse from elsewhere. Move furniture and equipment from your current office, or buy from reclaimed sources.
4. Buy remanufactured. Products rebuilt by the manufacturer or a specialist, often with a warranty.
5. Buy new, carefully. Choose products with published environmental data, replaceable parts and a take-back route.

This order matters because some Cat A elements carry a lot of carbon. In a 2024 study of Cat A fit-outs, the architects AHMM found that the raised access floor alone accounted for about 29 kgCO₂/m² in three of the four designs they modelled ². A sound raised floor that stays in place avoids that carbon entirely.

Reused items still have to meet current Building Regulations and fire performance requirements, and you should check what warranty comes with them, so plan reuse early.

Circular furniture

Furniture is where occupiers have the most direct control. You can reuse your own furniture, buy refurbished or remanufactured items, use manufacturer take-back schemes, or lease furniture rather than own it. When you specify new pieces, ask for environmental product declarations, ask whether the product can be taken apart for repair, and ask how long spare parts will be available. Keep a simple inventory of what you have, so the next move starts from facts rather than a skip.

Embodied carbon: why fit-out matters

Embodied carbon is the greenhouse gas released in making, transporting, installing, maintaining and finally disposing of materials. The problem with fit-out is how often it is repeated.

The AHMM study put the upfront carbon of four Cat A designs at between 58 and 92 kgCO₂/m². It also found that small offices in the City of London have a typical lease length of 5.1 years, which implies around eight tenants, and potentially eight Cat A strip-outs, over a 60-year building life ². The Cat B work on top of each one adds further carbon.

Embodied carbon is not currently regulated for fit-outs in England, and the government has said it prefers a voluntary approach to whole-life carbon assessment. Recognised voluntary methods exist, however. RICS’s Whole life carbon assessment standard (second edition, in force since July 2024) sets out how to measure it. The UK Net Zero Carbon Buildings Standard, published in March 2026, includes upfront carbon and operational energy limits and allows landlords and tenants to claim conformity separately. At the least, ask your design team for an embodied carbon estimate of the main options, so you can compare them.

EPCs and MEES: where things stand in October 2026

In force now. Under the Minimum Energy Efficiency Standards (MEES), privately rented non-domestic property in England and Wales must have an EPC rating of at least E. Since April 2023 this has applied to existing lettings as well as new ones, unless a valid exemption is registered.

Confirmed as policy, but not yet law. The government’s interim response of 18 June 2026 set out the following ¹:

• buildings over 1,000 m² will need to reach EPC B by 2031, where cost-effective
• buildings below 1,000 m² stay at EPC E, with no set deadline for going further
• the previously proposed interim EPC C requirement for 2027 has been dropped
• the seven-year payback test and the existing exemptions will remain

All of this depends on secondary legislation passing through Parliament. Further detail, including how the 1,000 m² threshold will be applied, is due in a full government response ¹. Legal commentators note that other points remain open, including enforcement, a possible short exemption for buildings let as shell and core, and possible duties on tenants not to worsen a rating.

What this means in practice. MEES obligations sit mainly with landlords, but a tenant’s fit-out can affect a building’s energy performance, and many leases already restrict alterations that would lower the EPC rating. If your lease runs beyond 2031 in a larger building, ask the landlord how it plans to reach EPC B, and whether the cost might come back to you through the service charge.

Remember too that an EPC is a modelled rating of the building, not a measurement of the energy it actually uses.

What BREEAM, NABERS UK and WELL actually measure

BREEAM is BRE’s assessment of how a project is briefed, designed and delivered. It awards credits across areas such as energy, health and wellbeing, materials, water and waste, with ratings from Pass to Outstanding. In September 2026 BRE launched Version 7 of BREEAM Refurbishment and Fit Out. It includes a separate Fit Out standard for tenant-led interior projects, with scope that can cover fabric and structure, core services, local services and interior design, and it puts more weight on carbon and predicted energy use ³. A BREEAM rating tells you how well a project was specified and delivered. It does not measure the energy the building uses once occupied.

NABERS UK measures actual energy use in offices, based on at least 12 continuous months of metered data, and rates it from one to six stars. Three stars represents the market average and six is market leading. There are separate ratings for the base building, for a tenancy (typically lighting, power and any extra cooling) and for the whole building, and each rating lasts 12 months ⁴. If you want evidence that your own floor performs well, the tenancy rating is the one to look at.

WELL, run by the International WELL Building Institute, is about occupant health rather than carbon. Its distinguishing feature is on-site performance testing of air, water, light, thermal comfort and sound. For most projects, testing is done after occupation, once the space is at least half occupied ⁵. A WELL rating says nothing about embodied carbon or energy use.

A simple test for greenwash is to ask what was measured, when it was measured, and who checked it.

Quick wins versus big decisions

Quick wins within a fit-out

• Audit existing furniture and fittings before any design starts.
• Replace carpet only where it is worn, rather than across the whole floor.
• Ask suppliers for environmental product declarations and take-back terms.
• Meter your tenancy’s energy separately so you can track it, and potentially rate it.
• Segregate site waste and agree reuse or donation routes for anything removed.

Big decisions that deserve proper analysis

• Whether to stay and refurbish or move, including the carbon cost of a whole new fit-out.
• Which building to choose: its EPC, any NABERS UK rating, and the landlord’s plans for 2031.
• Whether to accept, adapt or ask the landlord to leave out a speculative Cat A.
• Whether a certification is worth pursuing, and which one matches what you want to prove.

Sources

1. GOV.UK, Minimum Energy Efficiency Standards (MEES) in the non-domestic private rented sector: interim response (18 June 2026)
2. AHMM, Fit Out Rip Out: A Study on the Carbon Cost of Cat A (March 2024)
3. BRE, BRE launches BREEAM Refurbishment and Fit Out Commercial Version 7 (September 2026)
4. NABERS, NABERS UK Energy for Offices Rules, Version 2.0 (March 2023)
5. International WELL Building Institute, WELL Performance Verification Guidebook (Q3 2025)

The regulatory position was checked against the sources listed in October 2026. The 2031 EPC B requirement still depends on secondary legislation, so check the current position before relying on it.