Mayfair — covered by Westminster City Council.
Planning permission drawings delivered by an MCIAT chartered team.
Building regulations drawings delivered by an MCIAT chartered team.
Loft conversion drawings delivered by an MCIAT chartered team.
House extension drawings delivered by an MCIAT chartered team.
Mansard roof extensions delivered by an MCIAT chartered team.
Garage conversion drawings delivered by an MCIAT chartered team.
Basement conversion drawings delivered by an MCIAT chartered team.
Structural calculations delivered by an MCIAT chartered team.
Measured building survey delivered by an MCIAT chartered team.
Party wall services delivered by an MCIAT chartered team.
Rear dormer drawings delivered by an MCIAT chartered team.


W1K primarily covers Mayfair in Westminster.
Decisions for W1K are made by Westminster City Council. Standard Permitted Development rules apply for most rear extensions and loft conversions on terraced and semi-detached houses, unless the property is in a conservation area, is listed, or sits under an Article 4 Direction. Article 4 in Westminster: Yes.
Building regs from £950. We do not charge hourly. Free site survey across all W1K addresses.
From first call to planning decision: typically 12–14 weeks. Site survey week 1, design weeks 2–3, validation 1–2 weeks, statutory 8-week determination. Westminster City Council timelines align with the national norm.
Mayfair in W1K is characterised by the housing stock of Westminster — broadly grand georgian and regency terraces in belgravia and pimlico.

Pick a slot that suits you. No obligation and no sales pressure, just straight answers on your planning route.
Every W1K postcode district we draw in, the stock that dominates it and the authority that validates a drawing package there. W1K fees below are the statutory England rates for 2026, not drawing package estimates.
| Postcode | Area | Dominant stock | What it means for a drawing package |
|---|---|---|---|
| W1K | Mayfair | Georgian townhouses, listed buildings | A drawing package at an W1K address in Mayfair is determined by Westminster City Council under its own Local Plan policies for Mayfair. |
| NW8 | St John's Wood | Victorian villas, mansion blocks | Adjoining district to W1K, also inside Westminster for drawing package purposes. |
| SW1A | Whitehall / Buckingham Palace | mixed stock | Adjoining district to W1K, also inside Westminster for drawing package purposes. |
| SW1E | Victoria | Regency terraces, post-war flats | Adjoining district to W1K, also inside Westminster for drawing package purposes. |
| SW1H | St James's Park | mixed stock | Adjoining district to W1K, also inside Westminster for drawing package purposes. |
Roof pitch, wall build-up and plot depth change every few W1K streets, and each one changes what a drawing package can achieve at that address.
W1K (Mayfair) conservation designations: there are 56 across Westminster City Council, Marylebone, Pimlico, Soho among them. Designation costs a W1K (Mayfair) owner the permitted-development route: a drawing package then needs a £548 householder application over 8 weeks, in place of the £249 prior approval route that takes 6 weeks. Covent Garden is the W1K (Mayfair) designation that most often changes a drawing package design.
What Article 4 removes near W1K (Mayfair): Multiple Article 4 Directions — office-to-residential restrictions, HMO conversions, retail to residential in shopping zones. Before pricing a drawing package we check whether the W1K address is inside the mapped area, because Westminster City Council draws the W1K (Mayfair) boundary street by street rather than across the whole of W1K (Mayfair).
Digging below a W1K (Mayfair) property: Westminster basement policy restricts to single-storey, typically under 50% of rear garden footprint; lightwells and rooflights strictly controlled in conservation areas. Where a drawing package in W1K (Mayfair) involves excavation that is read beside the Party Wall etc. Act 1996, which needs two months notice for a W1K (Mayfair) dig within 3 m of a neighbour, and Westminster City Council expects the W1K ground conditions addressed in the application.
W1K (Mayfair) housing stock: Grand Georgian and Regency terraces in Belgravia and Pimlico; Victorian and Edwardian mansion blocks; heritage-rich townhouses throughout; very high listed building density. Heritage-first planning approach; listed buildings on almost every street; basement and rear extension policies particularly strict. Read that before choosing a drawing package route in W1K (Mayfair) — construction, not postcode, sets what is achievable. Westminster City Council charges £548 for a householder application and has 8 weeks to determine it.
Sources for this W1K drawing package page: borough policies maps and conservation-area registers (2025–26), Royal Mail postcode district boundaries, the Town and Country Planning (Fees for Applications) (England) Regulations, the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended, and the Party Wall etc. Act 1996.
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