Technical Guidance

Expanding on and explaining the NHBC Standards

To help you interpret and apply the NHBC Standards we produce the following Technical Guidance Documents. They each expand on and explain a specific part of the NHBC Standards.

They are designed for use by competent construction industry workers and are for general guidance only. They do not constitute professional advice.

All information relates to circumstances prevailing at the date of publication and will not be updated to reflect subsequent developments.


New home built alongside existing home
Japanese Knotweed
Conversions and renovations

NHBC Standards Chapter 4.2 Building near trees

Strip/trench fill foundations - slip membranes

NHBC Standards Chapter 4.3 (formerly Ch 4.4) Strip and trench fill foundations

Foundation concrete
Steps in foundations
Strip and trench fill foundations on level sites

NHBC Standards Chapter 4.4 (formerly Ch 4.5) Raft, pile, pier and beam foundations

Raft foundations - edge detail

NHBC Standards Chapter 5.2 Suspended ground floors

In-situ concrete suspended ground floors
Precast concrete floor planks to ground floors
Radon protection - provision of sump
Ventilators in compartment walls beneath suspended ground floors

NHBC Standards Chapter 5.3 Drainage below ground

Drainage - connections to pre-formed inspection chamber bases
Lightweight drainage covers
Access to manholes/inspection chambers
'Y' junctions in drains under buildings
Field drainage systems in septic tanks and small private sewerage treatment plants
Underground drainage - pipe cross-overs

NHBC Standards Chapter 5.4 Waterproofing of basements and other below ground structures

Waterproofing of basements and other below ground structures

NHBC Standards Chapter 6.1 External masonry walls

Partial fill insulation to gable walls
Small pediment gable walls
Cavity trays to openings with soldier courses or stone lintels
Dpc trays to rendered walls (Revised March 2017)
Installation of lead flashings
Bedding lintels
Movement joints below dpc
Restraint straps to gable walls of garages
Damp proofing around meter boxes
Movement joints in clay brick masonry
Cavity trays to bay windows
Masonry bed joint reinforcement
Toothing of brickwork
Concrete fill in a cavity wall
Ducts/flues through core drilled holes
Block bonding
Movement joints in masonry - timber framed external walls 
Lintels within coastal sites
Lintels  to walls over drive-through access to houses (England and Wales)
Lintels over wide garage openings
Wall ties at movement joints
Face fixed restraint straps to gable walls in buildings
Air bricks to underfloor voids - relationship to ground levels
Movement joints in masonry walls
Forming stop ends to cavity trays
Thin joint mortars
Wall ties at jambs with full fill cavity board insulation
Stone coursing and wall ties (NEW October 2018)
Fixing tiling battens to masonry (NEW October 2018)

NHBC Standards Chapter 6.2 External timber framed walls

Socket outlets - fire barriers
Ventilation of cavities
External timber framed walls - movement gaps at eaves and verges
Rendering on timber framed walls

NHBC Standards Chapter 6.3 Internal walls

Firestopping to garage walls
Separating walls - cavity insulation (withdrawn pending review March 2016)
Dpcs under timber soleplates to internal partitions
Separating wall construction within roof spaces
Timber stud partitions
Sockets and switches in light steel framed separating walls

NHBC Standards Chapter 6.4 Timber and concrete upper floors

End support to chipboard flooring
Noggings for lateral restraint straps
Bolt fixing of multiple joists
Strutting to floor joists
Sealing around ends of engineering joists
Support of plasterboard
Support of joist hangers
Recessed light fittings in ceilings to intermediate floors in houses
Lateral restraint straps to beam and block and precast or prestressed intermediate floors

NHBC Standards Chapter 6.5 Steelwork

Steel beams - parallel connections
Perforated padstones

NHBC Standards Chapter 6.6 Staircases

Handrail to staircases - tapered treads/winders (Revised October 2018)
Stair nosings
Guarding to treads and risers
Risers to private stairs - thick floor coverings
Nosings to stairs in common areas

NHBC Standards Chapter 6.7 Doors, windows and glazing

Gaps around windows (Revised March 2017)
Background ventilation to utility rooms
Gaps around timber windows and timber door frames
Door between an integral garage and the dwelling - security
Egress windows and conservatories
Fire doors to bathrooms
Window restrictors and protection against falling 
View outside main entrance door
Door Ironmongery - Students accommodation
Door limitation devices
Marking of insulating glass units
Marking of safety glass

NHBC Standards Chapter 6.8 Fireplaces, chimneys and flues

Installation of gas flue pipes in roof spaces
Guarding to gas flue terminals
Termination of horizontal flues

NHBC Standards Chapter 6.9 Curtain walling and cladding

Curtain walling formed from stacked windows and spandrel panels

NHBC Standards Chapter 7.1 Flat roofs and balconies

Balcony drainage
Timber balconies and terraces (Revised October 2018)

NHBC Standards Chapter 7.2 Pitched roofs

Diagonal bracing to double hipped roof
Plasterboard fire-resisting ceiling in contact with single leaf masonry
Use of nail guns for fixing trussed rafter bracing
Wall plates - bedding, lengths and joints
Bedding verge tiles
Lateral restraint provided by gable ladders (Revised March 2017)
Bracing of mono-pitch roof trusses
Pitched roofs - bedding verge undercloaks
Attic trusses - bracing
Pitched roofs to garages - holding down straps
Roofng underlay at eaves level
Ventilation of small roofs
Fixing valley trussed rafters (diminishing trussed rafters)
Canopy flashings
Diagonal bracing to trussed rafters
Fixing roof tiles in valleys
Loft hatches and fire resistance
Vapour permeable underlays (VPUs) and roof void ventilation (withdrawn December 2016. Now covered by VPU high level ventilation in Standards)
Fixing tiling battens using nail guns
Slate hook fixing 
Tiling battens
Access to roof voids
Spandrel panels to cold roofs (January 2018)
Eaves ventilation trays and VPU’s (NEW October 2018)

NHBC Standards Chapter 8.1 Internal services

Discharge pipes from UVHWSS in garages
Earth bonding - certificate of compliance
Pipe insulation in airing cupboards
Earth bonding plastic plumbing
Use of flexible ducting to connect SVP
Insulation of heating pipes in timber floors
Electrical - earth bonding metal back boxes
Sound insulation of soil pipes in floor voids
Extract fans - air leakage
Plastic plumbing - pipe support
Plastic plumbing - insulation
Air Admittance Valves
Wiring to wall lights
Consumer unit - labelling
Metal splashbacks - earthing/bonding
Sound proofing to SVP's 
Support to cables in cable trays
Electrical fittings near cookers, sinks and wash basins
Consumer units - blanking pieces
Tracer tapes to plastic water pipes
Rodding access to soil and vent pipes (Revised March 2017)
Discharge pipes from unvented hot water storage systems
Protection of electric cables in walls or flat and sloping ceilings
Disconnection of built-in kitchen appliances
Flush mounted electrical accessories in partitions (NEW March 2017)
Mounting height consumer units (NEW October 2018)

NHBC Standards Chapter 9.2 (formerly Ch 8.2) Wall and ceiling finishes

Edges of ceramic tiling
Dry lining to walls with chemical dpcs
Dry lining walls with different types of masonry
Edge sealing to dry lining

NHBC Standards Chapter 9.3 (formerly Ch 8.3) Floor finishes

Fibre reinforced screeds

NHBC Standards Chapter 10.1 (formerly Ch 9.1) Garages

Garage - concrete floors
Garage wall construction
Compartment walls between garages (Revised March 2017)
Carports - fire separation

NHBC Standards Chapter 10.2 (formerly Ch 9.2) Drives, paths and landscaping

Log retaining walls (withdrawn January 2016. Now included in NHBC Standards)
Profles for access steps
Disabled access to principal entrances (England and Wales)
Pedestrian access
Guarding to retaining structures
External steps - mobility access (England and Wales)
Retaining walls across private gardens
Guarding to retaining structures in communal areas
Handrails to steps in paths (withdrawn January 2016. Now in NHBC Standards)
Paths used for the removal of refuse (Revised March 2017)