How to Prepare Your Bathroom for the Future Homes Standard 2026
The Future Homes Standard is the 2026 step-change in Building Regs L (energy) and F (ventilation). For a renovating homeowner, the bathroom is the room that touches the most FHS levers in one go — hot water, ventilation, fabric and water demand. Get these four right at renovation and you avoid a £4,000-£8,000 retrofit when the rules harden.
Four FHS Levers Every Bathroom Touches
The Future Homes Standard pushes UK new-build emissions toward 75-80% lower than 2013 baseline by 2026. For renovations, the same levers are the smart targets at refurb stage — far cheaper now than retrofit.
Specify a 180-250 L unvented cylinder with twin coils & immersion. Works with current combi today, ready for ASHP swap tomorrow.
Basin tap ≤8 L/min, shower ≤9 L/min, dual-flush WC 4/2.6 L. Hits the FHS 105 L/person/day household target.
Continuous-running dMEV at 8 L/s, or MVHR branch with insulated duct. Replaces noisy intermittent fans and meets Part F 2026.
Add 80-100 mm PIR behind the tile-backer board on external walls. Negligible footprint cost, big U-value win.
The 7-Step FHS-Ready Bathroom Renovation
Step 1 — Audit current spec (Day 0)
Note the existing boiler type, hot-water demand, extract fan rating and external-wall construction. This drives the upgrade list.
Step 2 — Choose hot-water route (Week 1)
If you're on a combi, plan for a future move to ASHP + cylinder. Pre-route 22 mm cold and 28 mm primary feeds even if the cylinder isn't installed yet — first-fix only adds £180.
Step 3 — Specify low-flow brassware (Week 1)
Pick TMV3 thermostatic mixers with flow regulators. Hansgrohe EcoSmart, Grohe SilkMove ES and Ideal Standard EcoTherm all hit the FHS targets.
Step 4 — Plan the MVHR / dMEV branch (Week 2)
Specify Vent-Axia Lo-Carbon Sentinel Kinetic or equivalent. Insulated duct (25 mm) where it crosses cold zones. dMEV must run continuously at 8 L/s with 26 L/s boost.
Step 5 — Insulate behind the tiles (Week 2)
Replace plasterboard on external walls with 80-100 mm PIR + 12 mm tile backer (e.g. Marmox or Wedi). U-value drops to ~0.18 W/m²K — meets 2026 spec.
Step 6 — LED Part L lighting (Week 3)
≥75 lumens/watt fittings, 2700-3000 K, IP44 in zone 2, IP65 in zone 1. Notify under Part P (your electrician's scheme).
Step 7 — Commission & document (Week 4)
Ask for the air-flow test certificate (Part F), the Building Regs notification (Part P), and a written list of brassware flow rates. File these with your EPC for resale.
What FHS-Ready Adds to a Standard Bathroom Refurb
| Upgrade | Standard 2025 cost | FHS-ready 2026 cost | Net premium |
|---|---|---|---|
| Hot water (cylinder pre-pipe) | £0 | £900 – £1,600 | +£1,200 avg |
| Low-flow brassware | £450 | £550 – £800 | +£200 avg |
| Continuous dMEV / MVHR | £90 fan | £340 – £690 | +£420 avg |
| External-wall PIR | £0 | £550 – £950 | +£700 avg |
| Total premium | — | — | £1,800 – £3,500 |
Avoids a future retrofit estimated at £4,000-£8,000 once the gas-boiler ban hardens from 2028 and FHS Part L applies to extensions/material renovations.
Future Homes Standard Bathroom FAQ
FHS is mandatory for all new dwellings from 2026 in England. For renovations, Building Regs Part L1B and Part F still apply and are tightening in step — pre-empting FHS spec at renovation stage is far cheaper than retrofitting later.
Household design target: 105 litres per person per day. Means basin taps ≤8 L/min, showers ≤9 L/min and dual-flush WCs at 4/2.6 L. Most reputable brassware ranges have FHS-compliant variants.
No. Modern dMEV units (Vent-Axia Lo-Carbon, Nuaire Cyfan, Greenwood CV2GIP) run at 19-23 dB continuously — quieter than ambient. They only ramp up on humidistat or PIR trigger.
No — all four FHS upgrades are internal. Building Regs apply (Part L, F, P) and your installer notifies under Competent Persons Schemes.
Hard data is still emerging, but EPC-A and FHS-aligned features are showing 1.5-3% price premiums on 2026 listings, particularly for buyers concerned about future retrofit costs.
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