The government released the conclusion of the Future Homes Standard Consultation on Tuesday – Link
I have had time to skim it and here are what I consider to be the key points:
Part L – Energy (Download)
- Zero carbon ‘ready’ by 2025 (Domestic and Non-Domestic). New Part L intent to be regulated Dec 2021 / coming into effect June 2022, then again in 2024, with Future Homes Standard fully implemented in 2025.
- Heat pumps encouraged as the primary heating technology for new homes – industry to be supported by the government.
Gas boilers to be phased out by 2025. - 31% lower carbon emissions for new homes (L1A Regs) from 2021 compared to current regs.
- Fabric First Approach to be strengthen (by tougher limiting U-values).
- Local Authorities will retain power to enforce local efficiency targets.
- Encouragement to design new heating systems to operate at flow-rate temperature of 55°C or lower.
- SAP 10.3 to be adopted – updated methodology with hopefully more accurate predictions on heating demand.
- BEIS’s Domestic energy price indices to be used in SAP 10 to calculate running costs.
- Thermal Bridging: Government-approved Construction Details to be removed – bespoke calculations will be required, or performance penalised.
- Further guidance to be issued to close the performance gap – Build Quality guidance.
- Signed standardised compliance report and photographic evidence criteria to Building Control for as built dwellings.
Overheating (Approved document )
- Guidance for prevention of Overheating in residential units to become adopted into Building Regs (as Part [X])
- Two requirements will be set:
Overheating requirement [1] relates to modeling the overheating risk
Overheating requirement [2] relates to the ability to open windows in relation to noise pollution, security - Overheating requirement [1] not set yet by the government, though developers can use the simplified method or the dynamic thermal analysis to show compliance
- The country split into 2 areas: England & Greater London
Each residential unit (or common area/corridor) to be split in 2 groups:
Group A: more than 2 fabric elements & openings in opposite facades (cross ventilation
Group B: 2 or fewer fabric elements & no cross ventilation
Two Methods of compliance
Simplified method:
1. Minimising solar gains:
If shading is required, par. 1.9 indicates the provision of 1 of the below:
- External shutters with means of ventilation
- Glazing with a maximum g-value of 0.4 and a high light transmittance of 0.7
- Overhangs with 50° altitude cut-off on due south-facing facades only.
2. Removing Excess Heat:
Group A should have a minimum free area of one of the following:
- 12% of the floor area, If the glazing area is less than 13% of the floor area
- Equal to the glazing area, If the glazing area is more than 13% of the floor area.
Group B should have a minimum free area of the larger of the following.
- 12% of the floor area
- The glazing area.
Openings should be designed to open to a minimum of 60 degrees.
A system for purge ventilation should be provided in each habitable room.
Dynamic Thermal Analysis: (more flexibility in design solutions)
CIBSE TM59 to be followed & submitted to Building Control
- Minimising solar gains:
Solar gains to be limited through any of the following:
- Fixed shading devices, for example shutters, external blinds, overhangs, awnings.
- Glazing design, for example size, orientation, g-value, size of window reveal.
- Building design, for example, the placement of balconies.
- Shade of adjacent permanent buildings, structures or landscape.
Internal blinds and curtains and trees should not be accounted to meet the criterion (not yet set by the government)
2. Removing Excess Heat:
- Opening windows, made more effective by cross-ventilation.
- Ventilation louvres in external walls.
- A mechanical ventilation system.
Active cooling not encouraged, but allowed
A system for purge ventilation should be provided in each habitable room, regardless of the method of assessment.
Overheating requirement [2] (not yet set by the government) must be met and take into account:
- Noise at night (23:00-7:00):
- When openings are used
- 40 dB LAeq, T, averaged over 8 hours.
- 55 dB LAFmax, maximum no more than 10 times a night.
- When a mechanical system is used
- 30 dB LAeq, T, averaged over 8 hours
Pollution: buildings near to significant pollution sources to be designed with guidance Section 2 of Approved Document F, Volume 1: Dwellings
Security: ground floor and easily accessible bedrooms must have louvered doors or window railings if openable windows are used to mitigate overheating
Protection from falling: handles with specific design and guarding (shutters or fixed guarding) should be installed
Protection from entrapment
Information to be provided to homeowners / Home User Guide
Article Published on January 21, 2021
Source provided here
Subscribe to our newsletter for our latest Blog, updates and £100’s given away every month here
Follow us on LinkedIn, Instagram, Facebook and listen to The Building Services Podcast