30 guides
Structural engineering guides for London homeowners
Plain-English answers to the questions we are asked most: walls, cracks, lofts, extensions, foundations, sewers, basements and party walls.
Extensions and alterations
Extensions and alterationsDo I need a structural engineer to remove a wall?If the wall holds up anything above it, yes. This guide explains how to tell, what the engineer produces and what has to happen before the wall comes down.Extensions and alterationsLoft conversion structural guide: what your engineer designsA loft conversion changes how the roof and top floor carry their loads. This guide explains the structural work behind the main loft types and what Building Control will want to see.Extensions and alterationsRear extension structural guide for London homesA rear extension is more than a new room. It changes the back of the house, the ground beneath and sometimes the neighbour's wall. Here is what the structural design covers.Extensions and alterationsBasement conversions in London: a structural guideLowering an old cellar or digging a new basement is the most involved structural project most homeowners take on. Here is what it involves, which approvals apply and where the engineering risks lie.Extensions and alterationsConverting a house into flats or an HMO: the structural sideTurning a London house into self-contained flats or a house in multiple occupation changes how it is used, loaded and divided. Here is what that means structurally and which approvals to expect.Extensions and alterationsChimney breast removal: what is involved and how to do it safelyTaking out a chimney breast can free up useful space, but whatever is left above still needs holding up. Here is how removal is designed, approved and built, and what to check if it has already been done.Extensions and alterationsSteel beams and padstones explainedA steel beam carries the load from the structure above across a new opening, and a padstone at each end spreads that load safely into the wall below. Both have to be designed together, because a strong beam on a weak bearing still fails.Extensions and alterationsMansard roof extensions: a structural guideA mansard replaces the existing roof with a new top storey, so the engineer has to design a new floor and roof frame and confirm that the walls and foundations below can carry the extra weight. This guide covers each step and the decisions that shape the design.Extensions and alterationsAdding a storey to a building: a structural guideYou can often add a storey to a house, block of flats or mixed-use building if the existing walls and foundations can carry the extra load. The first step is a capacity check, and the answer shapes everything from the planning drawings to the choice of frame.Extensions and alterationsTemporary works and propping: keeping a building up during alterationsWhenever a builder removes a wall, cuts in a beam or digs beside a foundation, something has to carry the load in the meantime. That temporary support is a design job in its own right.Extensions and alterationsSide return extensions: a structural guide for terraced housesInfilling the narrow strip beside a terraced house's back addition is one of London's most popular extensions. Structurally it hinges on a long beam, a boundary wall and what is under the ground.Extensions and alterationsGarage conversions: what the structure needsTurning a garage into a room looks simple, but garages were rarely built to the standard of the house. Here is what an engineer checks, from the old door opening to the floor and foundations.Extensions and alterationsTurning a flat roof into a roof terrace: the structural questionsA flat roof built for occasional maintenance is not automatically strong enough to be a terrace. Here is how engineers check it, strengthen it and make sure the balustrade will hold.
Inspections and surveys
Inspections and surveysStructural engineer or building surveyor: which do you need?The two roles overlap, and the job titles confuse people. Here is what each one does, where they differ and how to decide who to call first.Inspections and surveysWhich structural inspection report do I need?Structural reports come in different depths, and the right one depends on how many issues you have and who will read the result. This guide sets out the options side by side.Inspections and surveysDo I need a structural report when buying a house?Most buyers do not need a structural engineer. Some do, and finding out late can delay an exchange or cost money. Here is how to tell which group you are in.Inspections and surveysHow much does a structural engineer cost in London?For most London homes, a structural engineer's visit with verbal advice starts from £300 + VAT, a beam design from £400 + VAT and a full loft or extension package from £800 + VAT. This guide explains what sits behind those figures and why some jobs cost more.Inspections and surveysRAAC: what property owners need to knowReinforced autoclaved aerated concrete was used in roofs and floors for several decades and can deteriorate with little warning. Most houses do not contain it, but some flats, extensions and mixed-use buildings might.
Planning and approvals
Planning and approvalsWhat are structural calculations and when do you need them?Building Control asks for them, builders work from them, and most homeowners never see inside them. Here is what structural calculations are and why they matter.Planning and approvalsBuilding over a public sewer: what to know before you extendMany London extensions are planned on top of a shared drain that has been a public sewer since 2011. Here is how to find out, what the sewer authority needs to see, and how engineers design around the pipe.Planning and approvalsThe Party Wall Act and structural works: a practical guideSteel beams into a shared wall, a loft conversion, a basement or an extension near the boundary will usually trigger the Party Wall etc. Act 1996. Here is what needs notice, how long it takes and where a structural engineer fits in.Planning and approvalsBuilding Control and structural work: what you need to knowAlmost any work that changes the structure of a home needs Building Control approval under the Building Regulations. This guide explains the routes to approval, what the inspector checks and how your engineer fits in.Planning and approvalsRetrospective Building Regulations approval for structural workIf a wall was removed, a loft converted or an extension built without Building Control approval, the usual fix is a regularisation application to your council. Here is how it works and where an engineer fits in.Planning and approvalsDrainage strategies for planning applications in LondonLondon councils increasingly expect a drainage strategy with planning applications for new homes and larger schemes. Here is what one contains, when you need it and how to make it work on clay.
Cracks and movement
Cracks and movementAre cracks in my house serious?Nearly every house has cracks. The skill is telling the harmless ones from the few that need attention, and knowing what to do about those.Cracks and movementSubsidence: the signs to look for and what to do nextNot every crack is subsidence, but some patterns are hard to ignore. Here is how to recognise the warning signs, what to do first, and what an investigation and repair usually involve.Cracks and movementWall tie failure: the signs and what to doThe classic sign of wall tie failure is a pattern of horizontal cracks in the mortar joints of a cavity wall, repeating at regular heights up the wall. It is a slow problem, but it gets worse with time, and an early survey keeps the repair simple.Cracks and movementBay window movement: causes, signs and repairsBay windows crack and move more than the rest of a house because they usually sit on shallower foundations, carry less weight and catch the worst of the ground's seasonal movement. Most cases are repairable, but the right fix depends on whether the cause is below ground or above it.
Foundations and ground
Foundations and groundLondon Clay, trees and foundations: what homeowners need to knowMost of London sits on a clay that swells when wet and shrinks when dry. Add a thirsty tree and shallow Victorian footings, and you have the most common cause of foundation movement in the city.Foundations and groundWhat is underpinning, and when is it needed?Underpinning means deepening or strengthening the foundations of an existing building so they bear on firmer or more stable ground. It is a well-proven repair, but it is often not the first answer, and choosing the right method matters as much as the decision to do it.