What your builders receive

Provide welfare facilities, secure hoarding to rear garden, protection to retained floors and side access for the duration of the works.

Provide skips for all waste arising with waste transfer notes retained and provided on completion.

Provide a proposed programme showing structural opening, weather-tight stage, service interruptions and handover. Maintain safe access to occupied areas, segregate work areas and agree any temporary loss of kitchen facilities before commencing.

List exclusions and assumptions separately. Identify who supplies each finish and appliance. Confirm responsibility for Building Control liaison, inspection booking and certification; do not conceal unconfirmed work within a fixed lump sum.

Take down existing rear wall between kitchen and garden to form new 5.2m opening, with temporary propping, to engineer's details.

Locate existing electricity, gas, water and drainage before demolition. Arrange safe isolation by competent trades and protect retained services. Raise a clarification if any concealed service conflicts with the proposed opening.

Prepare a temporary works sequence for the structural opening, maintain stability and provide weather protection until the new structure is enclosed. Temporary works design responsibility is to be stated in the return.

Excavate and construct concrete trench-fill foundations to depth agreed with Building Control.

Allowance for additional depth should ground conditions or nearby trees require it.

Is there a tree within 10m of the extension? Has a trial pit been dug?

Inspect formation before placing concrete and record Building Control acceptance. Stop and seek direction where made ground, roots, groundwater or unexpected obstructions are encountered; describe the proposed basis for any additional allowance.

Divert existing foul drain around new footprint with new inspection chamber.

Maintain access for future rodding and inspection. Test new foul drainage before covering and provide a record of test results. Confirm any sewer ownership or build-over approval required before altering the existing route.

Is the affected drain private or a public sewer, and is build-over approval required?

Ground-bearing slab with DPM, 120mm PIR insulation and 75mm screed ready for underfloor heating.

Lap the damp-proof membrane to the wall damp-proof course and seal penetrations. Coordinate thresholds, floor levels and insulation junctions to avoid damp bridging. Refer any conflicting levels to the designer before construction.

Facing brick outer leaf to match existing, 100mm full-fill insulation and block inner leaf.

Allow for suitable wall ties and connection to existing masonry, cavity closures at openings and continuous insulation at junctions. Match facing material using a sample agreed with the homeowner before ordering.

Supply and install steel beam on padstones, with fire protection, to engineer's design.

Confirm fabricated steel matches the current engineer's details; retain identification and relevant installation records. Arrange inspection of bearings and connections before enclosing, and provide photographic records for handover.

Warm-deck flat roof with single-ply membrane, insulation to Part L, aluminium trims and rainwater goods.

Supply and fit two fixed rooflights in the flat roof.

Rooflight size and model not shown. Confirm make, size and whether opening.

Coordinate roof falls, outlets and rainwater discharge with the drawings. Complete membrane junctions to the system manufacturer's instructions and provide the stated roof warranty. Raise any missing outlet or overflow detail before installation.

Supply and fit 4.8m aluminium bi-fold doors, anthracite grey, double-glazed.

Include perimeter sealing, suitable closers and making good around the doors. Coordinate the threshold with the external level and drainage. Provide product data, safety glazing confirmation, warranties and commissioning instructions.

Wet underfloor heating to the new extension, connected to the existing boiler.

Check existing heat source and controls are suitable for the proposed underfloor heating. State any boiler modification or replacement separately; flush, test and commission the new circuit and hand over operating instructions.

Has the existing boiler capacity and suitability for the additional heating load been verified?

Connect homeowner-supplied sink, dishwasher and appliances to agreed service locations. Allow for accessible isolation valves and leak testing. Confirm appliance specifications and any water treatment requirements before first fix.

New kitchen circuits, 12 downlights, sockets to kitchen layout, external light. Part P certificate.

Agree socket, appliance isolation, lighting and switching positions against the final kitchen layout before first fix. Verify capacity and condition of the existing consumer unit and identify any upgrade separately.

Has the final electrical layout been approved and has the consumer unit been assessed?

Test completed circuits, label alterations at the consumer unit and provide the relevant electrical installation certificate and Building Regulations notification. Include operating information for new controls.

Plasterboard and skim to all new walls and ceilings, and make good to existing.

Use suitable boards and preparation at splash-prone locations; coordinate movement and junction details with the retained building. Prepare surfaces ready for the specified final finish and rectify defects before decoration.

Make good retained skirting and internal trim disturbed by the opening. Agree profiles, finish and extent of replacement before ordering, and state whether replacement rather than repair is allowed for.

Which existing skirting and trim are to be retained or replaced, and what profile is required?

Fit kitchen units, worktops and appliances supplied by the homeowner.

Obtain the approved supplier layout before setting out services. Agree delivery, storage, worktop templating and appliance connection dates; inspect homeowner-supplied items on receipt and report damage or missing components.

Supply and lay large-format porcelain floor tiles.

Splashback material, coverage and supply responsibility are not selected. Do not assume tiles, glass or stone; state an allowance or qualification pending the homeowner's selection.

What splashback material and extent are required, and who supplies it?

Confirm selected tile, pattern, grout and threshold treatment. Check screed suitability and moisture condition before installation, coordinate movement joints with underfloor heating and follow the adhesive manufacturer's system.

Confirm the tile selection, laying pattern, grout and transition to existing flooring.

Mist coat and two coats of emulsion to new walls and ceilings.

Agree colour and sheen samples with the homeowner. Protect installed doors, flooring and kitchen during painting; fill and prepare surfaces, maintain drying times and leave a small labelled quantity for touch-ups.

Reinstate the patio outside the new doors with a level threshold.

Patio size and paving material not specified.

Agree finished paving levels and junctions around the new opening. Confirm surface-water discharge and access requirements; avoid bridging the damp-proof course and identify any required drainage channel before pricing.

Confirm finished patio levels and whether a threshold drainage channel is specified.

Arrange inspections and obtain the completion certificate, plus electrical and gas certificates.

Assemble Building Control completion documentation, electrical certification, heating commissioning records and relevant product warranties. Identify any outstanding third-party inspection or approval before the proposed handover date.

Joint snagging inspection, builder's clean and handover of all certificates and warranties.

Record the joint snagging list, agreed rectification dates and contact for defect reporting. Demonstrate door operation, heating controls and maintenance points; confirm the contractual defects arrangements in the quotation.