Party Wall Surveyor Hounslow: Compare Quotes

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Post a Party Wall job for a property in the London Borough of Hounslow. The administrator reviews the complete enquiry and could invite suitable qualified surveyors to provide independent quotes when the comparison service is available.

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The 2015 Local Plan is still the adopted plan

Hounslow’s live Local Plan page identifies the Hounslow Local Plan 2015 to 2030, adopted on 15 September 2015, as the adopted plan.

The proposed replacement is not yet an adopted plan. Hounslow submitted its Local Plan 2020 to 2041 for independent examination on 23 June 2025. The council’s current examination page still describes it as the proposed submission draft, and the hearing pages list Stage 2 sessions from May to July 2026.

That distinction matters when reading search results. Proposed Policy SC7 in the replacement plan may carry weight according to its stage and unresolved objections, but it has not displaced adopted Policy SC7 of the 2015 plan. Address-specific planning advice should identify which adopted and emerging policies are being relied on.

The adopted Policy SC7 covers extensions, outbuildings, basements, paving and driveways. It supports work that maintains local character and avoids harm to neighbours, occupants and the built and natural environment. It is a planning policy. It does not determine whether notice is required under the Party Wall etc. Act 1996.

The 2017 extension guide has been superseded

Hounslow adopted the Character, Sustainability and Design Codes SPD on 14 May 2024. The council’s current supplementary-planning index says it supersedes three earlier documents:

the Residential Extensions Guidelines SPD of 2017;
the Shopfront Design Guidelines SPD of 2013; and
the Urban Context and Character Study of 2014.

The old 2017 residential guide still has a live council download page and appears in search results. It is not the document to use for a current proposal. The residential standards now sit in Part A5 of the 2024 SPD.

Three planning depths measured from the original rear wall

For a first single-storey rear extension, Part A5 sets maximum depths measured from the main rear wall of the original house. The measurement includes any roof overhang:

3.05 metres for a terraced house, including an end terrace;
3.65 metres for a semi-detached house; and
4.25 metres for a detached house.

These are the council’s planning-design figures for proposals assessed against the SPD. They are not a statement of permitted-development rights and are not Party Wall notice distances.

The same section says no part of the extension, including guttering, should cross or overhang the property boundary. For an infill extension that exceeds the normal maximum depth, the eaves on the shared boundary should not exceed 2 metres, and the roof should slope away from that boundary at no more than 45 degrees.

That 45-degree roof pitch is another planning-design measure. It is not the downward foundation plane used by section 6(2) of the Act.

First-floor rear work has different limits

A two-storey or first-floor rear extension on a mid-terrace will, according to Part A5, rarely be acceptable. An addition to an end terrace, semi-detached or detached home may be acceptable according to the site.

For the first-floor portion, the guide says:

its width should be no more than half the width of the original house;
it should not project more than 2.5 metres beyond the rear wall unless a daylight and sunlight analysis clearly demonstrates no harm;
it should sit at least 2 metres from the original side wall of a neighbouring property; and
it should be set off the shared boundary as far as possible while retaining that separation from the non-adjoining neighbour.

These tests address light, outlook, enclosure, scale and character. They do not create a two-metre exemption from the Act. Steel bearings cut into a party wall, work to raise or extend that wall, and qualifying excavation must be assessed under the relevant statutory provisions.

Hounslow’s basement code is unusually specific

Part A5 limits a basement to one subterranean floor and says it should not extend beyond the main front or side walls of the house.

For a larger property, it says a basement under part of the rear garden may be acceptable. The text calls the relevant measurement “depth”, but Figure A5.13 shows it horizontally from the rear wall into the garden:

3.05 metres for a terraced house;
3.65 metres for a semi-detached house; and
4.25 metres for a detached house.

Where the basement projects beneath the garden, at least 1 metre of soil should be reinstated above it for drainage and planting. A front lightwell should normally project no more than 1 metre from the front wall, and a rear lightwell no more than 2 metres from the rear wall.

The guide also says Hounslow will:

require a suitably qualified engineer to certify a Construction Method Statement where a basement is allowed;
expect that statement to address excavation, temporary works, construction techniques, neighbouring land, geology, hydrology, noise, dust and vibration;
oppose a new basement to a listed building in principle;
refuse use as a self-contained home, main living area or sleeping accommodation; and
require a site-specific Flood Risk Assessment in Flood Zones 2 and 3, and in Flood Zone 1 where evidence shows surface-water, groundwater or sewer-flood risk.

Those are planning requirements and constraints. A Construction Method Statement does not replace a notice, consent or award under the Act.

Hounslow’s 3.05 metres is not the Act’s 3 metres

Paragraph A5.63 says a Party Wall Agreement “may still be required” for a basement. That is a useful prompt, but it does not state the legal test.

For excavation, section 6 has two distinct routes:

within 3 metres, notice is engaged only where the proposed excavation will go below the bottom of the adjoining building’s foundations; and
within 6 metres, notice is engaged where part of the excavation will go below a plane drawn downwards at 45 degrees towards it from the bottom of the adjoining building’s foundations.

Distance alone is therefore insufficient for the three-metre test. The relevant depth is the excavation compared with the neighbour’s foundations, not Hounslow’s SPD planning projection into a garden.

The government’s explanatory booklet also separates the Act from planning permission and Building Regulations. Approval under one regime does not amount to compliance with another. The party wall notice guide explains how the notice types relate to the proposed work.

Twenty-nine conservation areas, but two householder directions

Hounslow states that it has 29 conservation areas. Its current conservation page identifies Bedford Park and Gunnersbury Park as the conservation areas with Article 4 directions restricting specified works that might otherwise be permitted development.

The council publishes property schedules and the withdrawn classes separately. Check the address and schedule rather than treating every Hounslow conservation area, or every property near an area boundary, as subject to the same restriction.

Conservation-area designation, an Article 4 direction and listed-building status affect the planning route. They do not decide whether a wall or floor is a party structure or whether proposed excavation meets section 6.

Almost half of households are in semis or terraces

At Census 2021, Hounslow recorded 102,961 households:

38,538 in a purpose-built block of flats or tenement;
29,477 in a semi-detached house;
21,123 in a terraced house;
6,540 in a converted or shared house;
5,022 in a detached house; and
2,261 across other converted buildings, commercial buildings and temporary accommodation.

Semi-detached and terraced houses together account for 50,600 households, or 49.1 per cent. Flats can also contain party structures: the statutory definition extends beyond walls to floors or other structures separating parts of buildings approached solely by separate staircases or entrances.

The census describes household accommodation. It does not establish the legal status or construction of any wall, floor or ceiling at a particular address.

The 1930s are the largest recorded build-period band

The Valuation Office Agency’s 2025 property-stock release records 111,270 Hounslow properties at 31 March 2025:

11,700 built before 1900;
6,510 built from 1900 to 1918;
9,230 built from 1919 to 1929; and
22,490 built from 1930 to 1939.

Those four pre-1940 bands total 49,930 properties, or 44.87 per cent of the stock. The 1930s are the largest single recorded band. VOA rounds the counts to the nearest ten and records properties on the Council Tax list, so its 111,270 total should not be substituted for the census household total.

Age can inform questions about likely construction and foundation investigation, but it cannot prove either. Establish the actual building form, shared structures and foundation levels for the property and its neighbour.

Explain the property and proposed work

Provide:

the full property address;
whether the property is terraced, semi-detached, detached or a flat;
which walls, floors or ceilings are shared, and with whom;
whether the property is listed, locally listed or in a conservation area;
whether the Bedford Park or Gunnersbury Park Article 4 schedule covers it;
whether the work involves a rear extension, infill, loft steel, dormer, chimney breast or boundary wall;
the planned rear projection and whether it is measured from the original wall;
whether any gutter, roof or other part approaches or overhangs the boundary;
whether excavation is proposed, its depth and its distance from neighbouring buildings;
the known or assumed depth of neighbouring foundations and the basis for that information;
whether a basement extends beneath a garden or includes lightwells;
the flood zone and any recorded surface-water, groundwater or sewer-flood risk;
any Construction Method Statement, engineering information, drawings and planning documents;
whether you are carrying out work or responding to a neighbour’s work;
notices, responses and correspondence already exchanged; and
known dates and access constraints.

The locality guide for Party Wall surveyors for Chiswick properties applies the adopted 2024 code to Chiswick’s mapped conservation areas and explains why Bedford Park needs an exact planning-authority check.

Compare the proposed appointment

Each quote should explain who would appoint the surveyor and the work included. That may involve reviewing drawings, notices, inspections, a schedule of condition, preparation of an award, liaison with another surveyor or later visits.

The Party Wall surveyor guide explains when a surveyor may be needed, and the Party Wall surveyor cost guide explains the factors that can affect the proposed fee. Nearby coverage includes Party Wall surveyors for Ealing properties and the wider Party Wall surveyor west London guide.

What happens after you post

Your verified enquiry is available to the administrator for review. Invitations are not currently available. In a later comparison service, a participating surveyor would receive only the outward postcode and a restricted brief before an authorised introduction.

When comparison is available, complete quotes and the surveyor’s private profile can be shown on your private customer page. Availability varies, so a request may receive several quotes, one, or none. Submission does not guarantee an invitation, quote or introduction.

If introductions are available and the administrator records your chosen introduction, only that surveyor receives your full contact and property details. FindTheSurveyor charges neither party a fee. You pay the professional fee directly to the surveyor.

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