Calculations signed by a chartered structural engineer for any domestic intervention in the borough: beams and lintels in steel, pad foundations, removed walls, the joists under a new loft floor, and underpinning where a basement demands it. Eurocode-compliant, ready for Building Control.
A rebuilt roof rather than an addition, so the calculations cover new floor loading at 1.5 kN/m², a new roof structure and usually a steel frame at the party walls. Wandsworth’s Datahub set records 2,310 mansard applications at 87% approved.
| Work | Calculations required | Basis |
|---|---|---|
| Mansard roof structure | Yes | Part A, new roof and floor |
| Loft floor to habitable use | Yes | 1.5 kN/m², BS EN 1991-1-1 |
| Steel frame at the party walls | Yes | Part A, plus a party wall award |
| Removing a load-bearing wall below | Yes | beam sizing and padstones |
| Wandsworth mansard applications | 2,310 | 87% approved |
| Full plans decision period | 5 weeks, or 2 months by agreement | reg 14 |
Sources: the Building Regulations 2010 (as amended), Schedule 1 Part A and regulation 14; Approved Document A; BS EN 1991-1-1 with its UK National Annex; the Party Wall etc. Act 1996; the Datahub row from the Planning London Datahub, retrieved 15 August 2026, phrase-matched and comparable within Wandsworth only. Read at 1 September 2026.
In Wandsworth — Extensive Victorian terraced streets — the classic London side-return extension opportunity; Edwardian villas around the commons; 1930s semi-detached in Southfields for the most part — a structural calculations package is the full measured-survey-to-submission drawing set London Borough of Wandsworth needs in order to determine an application: existing and proposed plans, elevations and sections at 1:100 and 1:50, a location and site plan, and the supporting statements the case officer asks for.
Prepared and reviewed by the architectural technologist team at Architectural Drawings London — CIAT Affiliate, professional indemnity insured.Last reviewed 2026-08-03.
Chartered structural engineer calculations for every residential intervention in Wandsworth — steel beams, lintels, pad foundations, wall removals, loft floor joists, underpinning. Eurocode-compliant, Building Control-ready.
Housing stock in Wandsworth: Extensive Victorian terraced streets — the classic London side-return extension opportunity; Edwardian villas around the commons; 1930s semi-detached in Southfields.
Character: Family-oriented, high side-return extension and loft conversion rates; planning department experienced with Victorian terrace modifications.
Article 4: Article 4 for HMO conversions covering the whole borough.
Removing a kitchen wall or opening two reception rooms into one needs a beam sized for the load above it and padstones that will carry the reaction. Both are designed, not selected from a table.
Ridge beam, purlin and dormer framing, plus the joist upgrade that converts a storage loft into a floor people may legally stand on. Nothing habitable gets signed off without that set.
Foundation design — pad, strip or trench fill — worked from the ground you actually have, the trees within influencing distance, and where the drains run.
Cutting a new window or door opening: the lintel is specified in steel, concrete or timber, and the bearing it needs at either end is calculated rather than assumed.
Basement work brings its own set: underpinning designed in sequence, a reinforced concrete slab, and retaining walls calculated for the soil and water pressure behind them.
A chartered structural engineer signs every calculation set that leaves here, CEng MIStructE or MICE. Building Control bodies take them on that basis, whether council-run or private.
Single planning or regs submission.
Planning + building regs + structural.
Listed, conservation, complex sites.
Move the controls for an indicative figure. It anchors your budget — it is not a quote. Every project is priced after a site survey.
Build costs are separate and quoted by your contractor. See our published fees.
Each postcode district we work in across the borough, what stands in it, and who validates a calculation package for an address there. One caution on the table: those are statutory England planning charges for 2026, and they say nothing about engineering fees.
| Postcode | Area | Dominant stock | What it means for a structural calculation package |
|---|---|---|---|
| SW19 | Wimbledon / Colliers Wood | Victorian villas, Edwardian terraces | SW19, covering Wimbledon and Colliers Wood, is divided between two authorities. Merton or Wandsworth may hold the file, so we read an SW19 address against both policies maps first. |
| SW11 | Battersea / Clapham Junction | Victorian terraces, mansion blocks | Battersea and Clapham Junction sit inside SW11, and Wandsworth Council validates every calculation package submitted from an SW11 address. |
| SW12 | Balham | Victorian and Edwardian terraces | Balham sits on the SW12 boundary, so a package there may be determined by Wandsworth or by Lambeth. The SW12 policies map decides which, street by street. |
| SW15 | Putney / Roehampton | Edwardian terraces, Victorian villas, mansion blocks | Putney and Roehampton fall in SW15, and the great majority of that district is Wandsworth territory, so Wandsworth Council is normally the validating authority. |
| SW17 | Tooting / Earlsfield | Edwardian terraces | Tooting and Earlsfield addresses in SW17 can go to Wandsworth or to Merton. The boundary runs through the district, and the SW17 policies map settles it street by street. |
| SW18 | Wandsworth / Earlsfield / Southfields | Victorian villas and terraces | SW18 covers Wandsworth town, Earlsfield and Southfields. All of it goes to Wandsworth Council, which applies the Local Plan policies drafted for those areas. |
| SW4 | Clapham | Victorian terraces, Edwardian villas | SW4 at Clapham straddles the boundary as well. Lambeth or Wandsworth may determine the work, so a SW4 address is checked on both policies maps before submission. |
| SW8 | South Lambeth / Nine Elms | Victorian terraces, new-build apartments | SW8 runs across South Lambeth and Nine Elms and is likewise divided. Lambeth or Wandsworth could be the determining authority, so the address is checked on both maps at the outset. |
Within a few streets in this borough the pitch changes, so does the wall build-up, so does how far the plot runs back. Every one of those changes what a calculation package has to account for.
Wandsworth conservation designations: 45 in all. Wandsworth Common is one, Clapham Common West another, Nightingale Triangle a third, and those are only the recognisable names. Designation takes away the shortcut. Work that would have gone through the six-week prior approval route instead needs a householder planning application decided over eight weeks, and the fees follow suit. The householder application fee in England is £548. The fee for a larger householder prior approval is £249. That is a genuine cost and a genuine delay, but it is not grounds to expect a refusal here. Across twelve quarters ending last March the council reached 3,107 householder decisions and granted 2,836 of them, a rate of 91.3% where the 33 boroughs pooled come out at 83.0%. Refusals over those three years numbered 271. Source: MHCLG live planning statistics
Wandsworth and Article 4: Article 4 for HMO conversions covering the whole borough. A structural calculation package planned at a SW11 address is checked against that direction first; Wandsworth Council publishes the Wandsworth extent, and the SW11 line rarely follows the Wandsworth boundary you would expect.
The building fabric around Wandsworth: Extensive Victorian terraced streets — the classic London side-return extension opportunity; Edwardian villas around the commons; 1930s semi-detached in Southfields. Family-oriented, high side-return extension and loft conversion rates; planning department experienced with Victorian terrace modifications. A structural calculation package in Wandsworth is scoped against that stock first, because it decides whether the scheme runs as permitted development, a £274 Lawful Development Certificate, or a full £548 application to Wandsworth Council.
Sources for this Wandsworth structural calculation 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.
Plain answers to the questions we field most weeks from homeowners across the borough about structural design.
Start a free quote →What you pay follows the scale of the intervention. Cheapest is one beam, sized for the wall you want gone. Take on a whole loft or extension and the set grows to include ridge beam, purlins, foundations and lintels, and prices accordingly. Basements and multi-storey schemes are quoted one by one. Chartered sign-off comes with every tier. See our fees.
Yes. Take out a load-bearing wall and something has to carry what it was carrying; the calculations are how you prove the replacement beam and its supports will manage. No Building Control body signs that work off without a chartered engineer's name against the arithmetic. Partitions deserve a look too, because in a Victorian terrace they are not always as non-structural as they appear.
Calculations follow one to two weeks after the architectural drawings and site dimensions reach us. Where a start date is pressing, we can turn a set round in three to five working days for a modest premium.
Two different documents, often confused. A structural survey looks at what is already standing and reports back on defects, on movement, on subsidence. Calculations do the opposite job: they design something not yet built — a beam, a foundation, loft steelwork. Extensions and loft conversions want the second kind. Calculations are what this practice produces; if a condition report is really what you are after, we will name someone who does those.
Yes. A good deal of our calculation work arrives with architectural drawings already prepared elsewhere, which is no obstacle at all. Where drawings and structural design are wanted from the same source, the Complete package covers both and costs less than buying them separately.
If your property sits on a boundary, here are the neighbouring options.
Survey, drawings, calculations and submission all sit with a single CIAT-affiliated team, which removes the handover where information usually goes missing.
A construction-ready drawing package compliant with every Approved Document — Part A structure, Part B fire, Part L thermal, Part M accessib...
Every loft type across every Wandsworth roof line — dormer, mansard, hip-to-gable, L-shape, Velux. LDC or full planning route, building regu...
The whole spectrum — rear extensions, side returns, wraparounds, double-storey, basement digs. Planning-led design with detailed technical p...
Wandsworth's most space-efficient loft solution when PD-route dormers are blocked. Our team designs mansards that get approved in ...
Turn your unused Wandsworth garage into a bedroom, home office or open-plan kitchen-diner. Planning route assessment, full building regulati...
Full architectural technology service for basement digs and cellar conversions in Wandsworth — structural underpinning design, waterproofing...
Measured surveys across Wandsworth — floor plans, elevations and sections to ±3mm accuracy. Leica Disto laser + BLK360 point-cloud scanning,...
End-to-end Party Wall Act 1996 service for Wandsworth — Section 1, 3 and 6 notices, schedule of condition surveys, party wall award coordina...
London's most popular loft type — the full-width rear dormer. Planning or Permitted Development route assessed for your Wandsworth property,...
Leave your number and an Architectural technologist will call you back within 30 minutes during working hours.
No obligation. No sales pressure. Just expert advice about structural calculations in Wandsworth.
Free quote in 60 seconds. No hourly billing. CIAT Affiliate.
Get my free quote →
