Listed Building Alterations
Works to Grade I and Grade II listed buildings, from minor internal alterations to significant structural changes — all carefully planned and consented.
Heritage & Listed Properties
Buildings that deserve to be treated differently.
Specialist heritage builders for listed buildings, period properties and conservation area homes across Essex, London and Suffolk.
Who we help
Owners of period and character properties across Essex, London and Suffolk.
We work with homeowners and developers who own listed buildings, period homes, barn conversions, character cottages and conservation area properties — buildings where standard builders simply do not have the experience or sensitivity required.
Heritage construction is a specialism, not an extension of general building work. The materials are different. The regulatory framework is different. The consequences of getting it wrong are significant — and often irreversible.
Our team has direct experience working across Essex, London and Suffolk with some of the region's most distinctive period properties — from Grade II listed farmhouses and Victorian terrace renovations to flint-wall boundary projects and oak-framed extensions to 17th-century cottages.
We work with:
- Listed Buildings — Listed building consent coordinated from application to completion
- Period Properties — Victorian, Edwardian, Georgian and earlier
- Character Homes — Cottages, farmhouses, barn conversions
- Conservation Areas — Article 4 directions and conservation conditions
- Historic Buildings — Pre-1919 construction requiring specialist knowledge
- Barn Conversions — Agricultural heritage structures sympathetically converted
Heritage across all three divisions
Our heritage expertise applies across every area of our work.
Period & Heritage Extensions
Extending a listed or period building is one of the most technically demanding types of project. We design and build heritage extensions that respect the host building's scale, material palette and architectural character — from oak-framed rear extensions to carefully proportioned single-storey additions in handmade brick and lime mortar.
- Handmade and reclaimed brick matching
- Lime mortar throughout
- Oak framed structures
- Natural slate and clay tile roofing
- Listed building consent management
Internal Remodelling
Renovating the interior of a period home is as much about what you preserve as what you change. We work carefully to retain original features — cornices, panelling, timber floors, sash windows and fireplaces — whilst introducing new kitchens, bathrooms and layout reconfigurations that serve modern family life without compromising the character of the building.
- Original feature preservation
- Lime plaster repairs
- Sash window restoration
- Period floor restoration and repair
- Sensitive structural alteration
Landscaping & External Works
The garden and external works of a heritage property are as important as the building itself. We design and build traditional hard landscaping — flint and brick boundary walls, reclaimed stone terracing, timber structures and period-appropriate planting — that respects the era and setting of the house.
- Flint and heritage brickwork walls
- Reclaimed stone and brick paving
- Pergolas and timber structures
- Traditional planted boundaries
- Sympathetic garden restoration
Typical heritage projects
What we are typically asked to do.
Oak Framed Structures
Bespoke oak frame extensions, garden rooms, porches and garages — designed to sit sympathetically alongside historic buildings using traditional joinery methods.
Traditional Brickwork
Handmade brick, reclaimed material matching, Flemish and English bond, tuck pointing and specialist facework — our masons understand historic brickwork.
Lime Mortar Repairs
Repointing, rebuilding and repair using appropriate lime mixes matched to the existing material — protecting historic structures from inappropriate cement.
Timber Frame Repairs
Structural timber repair, splicing and replacement using traditional carpentry. We work to preserve original fabric wherever possible.
Sympathetic Extensions
New additions designed to respect the scale, material palette and architectural character of the host building — making the new look as though it belongs.
Traditional Roofing
Clay plain tile, natural slate, peg tile and lead work — matching existing roof coverings and detailing to conservation area and listed building standards.
Heritage Garden Walls
Flint, stone, brick and mixed-material boundary walls built using traditional techniques — from simple repairs to complete new-build heritage walls.
Period Garden Restoration
Sympathetic hard landscaping for period and historic gardens — reclaimed stone, aged brick, traditional edging and planting that respects the era of the house.
Sensitive Internal Renovation
Preserving original features — cornices, architraves, sash windows, stone flags and timber floors — whilst improving the liveability of a historic interior.
Completed heritage work
Work we have finished, and what was heritage about it.
Photographed, with the scope written down. Where a property's designation is not stated below, it is because we hold documented evidence of the work rather than of the listing — and a grade we have not verified is not ours to publish.
Heritage Flint Wall
Colne Engaine, Essex · 2026Seventeen knapped flint panels set between brick piers, extending an existing flint and brick garden wall across a 750mm rise in ground level. The setting-out was worked backwards from the original panel spacing so the new run lines through symmetrically with the old — which is the difference between an extension and an addition.
See the project
Period Drawing Room Restoration
Coggeshall, Essex · 2025Failing plaster in a period drawing room traced to four external downpipes rather than treated as condensation. The brickwork behind them was repointed and colour-matched first, and only then were the walls replastered in lime, to the same method as the original — because gypsum on a solid wall traps the moisture and moves the problem along the wall.
See the project
Reclaimed Brick Fireplace & Oak Bressummer
Wickham St Paul, Essex · 2023A chimney breast opened up and rebuilt in reclaimed brick chosen to match the age and colour of the house, carried on a solid oak bressummer. The masonry above had to be supported before a brick came out, and the new opening sized around the stove and its flue.
See the project
The Old Rectory
Earls Colne, Essex · 2024A historic former rectory brought back from years as a rental property. The exceptionally old boundary wall set the approach for the whole scheme, and the sitting-room fireplace was rebuilt in corbelled brick under a stone lintel because a rectory of that age would have had one.
See the project
Village Projects
Coggeshall, Essex · 2024Ongoing work across the village, including heritage refurbishment to listed and historic properties on East Street — sash window and fabric repairs, and external shopfront and glazing restoration.
See the projectOur heritage work is concentrated in Essex, and this is the honest extent of the photographed portfolio rather than a selection from a longer list. See what we have built across Essex or all projects.
“The building came first. Our job was to work around it — not the other way around.”
Milad Mansouri, Founder
Our approach
Balancing original character with modern life — carefully.
1
Original Character
We start by understanding the history and character of the building before proposing any work. That means researching original materials, understanding the construction logic, and designing in a way that respects what is already there.
2
Modern Functionality
Heritage does not mean discomfort. We find ways to introduce underfloor heating, concealed insulation, modern kitchens and bathrooms in ways that do not compromise the character of the building.
3
Planning & Conservation
We work on listed and heritage properties across Essex, London and Suffolk, and we coordinate the consent process on your behalf — engaging Local Planning Authorities and conservation officers, and involving heritage consultants and other specialists where a project calls for them. We understand what is likely to be consented, how to present an application well, and how to keep the process moving.
4
Conservation Requirements
Our material specifications and method statements are prepared to meet conservation area conditions, listed building consent conditions and Building Regulations as they apply to historic structures.
5
High-Quality Craftsmanship
Heritage work demands a higher level of skill than standard new-build construction. We work with specialist craftspeople — masons, carpenters and decorators — who are experienced with traditional building methods.
Appropriate materials
Traditional masonry, and why the modern substitute causes damage.
Almost every serious problem we are called to on a period building was caused by a well-intentioned repair in the wrong material. Old buildings were built to move and to breathe; modern materials are designed to be rigid and sealed. Putting the second into the first is what turns maintenance into damage.
Lime mortar and lime plaster
Not cement mortar and gypsum plaster
A solid wall with no cavity has to be able to release the moisture it absorbs. Lime is soft and permeable, so it lets the wall breathe and it sacrifices itself rather than the brick or stone. Cement is harder than most historic brick: trapped moisture leaves through the face of the brick instead of the joint, and the face spalls off. The damage is permanent — you cannot put a brick face back.
Handmade and reclaimed brick, matched to the building
Not the nearest modern stock brick
Age, colour, texture and size all have to be matched, and so does the bond and the joint. A modern brick is dimensionally consistent in a way a handmade one never was, so even a correct colour reads as a patch. Where the repair is visible we match against the building itself rather than a sample board.
Knapped flint
Not cobbles or a flint-effect facing
Flint is knapped by hand, panel by panel, and it has to be tied properly back to the structure behind it — on the Colne Engaine wall, mesh ties were built into the single-skin sections as the brickwork went up. Flintwork that is simply bedded onto a face will eventually come off it.
Green oak, and solid oak for structural members
Not engineered timber or softwood with an oak finish
Green oak moves as it seasons, and it is jointed and pegged on the assumption that it will. Detailing it as though it were stable is what produces the splits and gaps people blame on the timber. Where a bressummer or lintel is carrying masonry it is solid, not a facing.
Natural slate and clay plain tile
Not concrete interlocking tile
Weight, coursing, gauge and the way the roof weathers all change with the material, and on a listed building or in a conservation area the covering is usually one of the conditions. Concrete tile is also heavier per square metre in most cases, which matters on a historic roof structure.
Breathable finishes and appropriate paints
Not modern impermeable coatings
Sealing the inside face of a solid wall with a vinyl or plastic finish undoes the benefit of lime beneath it. The wall needs a continuous path for moisture to leave by, and one impermeable layer anywhere in that build-up is enough to interrupt it.
Heritage settings and designations
What protects your building, and what that means in practice.
These are not interchangeable and they do not overlap neatly. We establish which apply to your property at survey stage, before any design work, because they change what is worth drawing.
- Listed building
The listing covers the whole building, inside and out, and normally anything attached to it. It is not limited to the elevation you can see from the road and it is not limited to the features specifically mentioned in the list entry — that entry identifies the building, it does not define the extent of protection.
In practice: Listed building consent is needed for any work affecting the building's special character. Removing a partition, replacing a window, changing a floor finish or altering a fireplace can all require it. Carrying out work without consent is a criminal offence and enforcement can require you to reverse it at your own cost.
- Curtilage
Structures within the curtilage of a listed building — an outbuilding, a stable, a boundary wall, sometimes a gate pier — can be protected as though they were part of the listing, even where they are not named in it and even where they are some distance from the house.
In practice: A garden wall or outbuilding you assumed was unrestricted may need consent. This is the single most common assumption we are asked to work around, and it is worth establishing before a design is drawn rather than after.
- Setting of a listed building
The surroundings in which a listed building is experienced. Your own property can sit within the setting of somebody else's listed building — and a scheme can be refused on the effect it has on that neighbouring building rather than on anything to do with your own.
In practice: Height, massing, roof form and the view from the public realm carry more weight than they otherwise would. Worth knowing before you fix on a design.
- Conservation area
An area designated for its architectural or historic interest. The buildings within it are not individually listed by virtue of the designation, but the council takes a view on how work reads from the public realm.
In practice: Materials, window design, roof form and boundary treatments come under closer scrutiny, and demolition and tree work are separately controlled. Schemes succeed when they are clearly sympathetic from the outset — arguing with a conservation officer after submission rarely works.
- Article 4 direction
A direction withdrawing specified Permitted Development rights across a defined area, most often used in conservation areas. It varies street by street, and two houses on the same road can be subject to different directions.
In practice: Work you would normally be able to carry out without an application needs planning permission. We establish which rights apply to your property at survey stage, before design work, because it changes what is worth drawing.
- Pre-1919 construction
Not a designation at all, but the practical dividing line. Solid walls, lime mortar, breathable construction and timber frames behave differently from anything built after them, whether or not the building carries any protection.
In practice: An unlisted Victorian house outside any conservation area still needs the materials and the methods to be right. Most of the technical content on this page applies to it.
This is general information, not advice on your property. Designations are recorded on the National Heritage List for England and by your local authority, and the only reliable answer for a specific address comes from checking both.
Who else is involved
Working with architects, engineers and conservation professionals.
Design and build means one contract and one point of contact — it does not mean one firm claiming every discipline. Heritage projects often need specialists we are not, and saying so at the start is cheaper for you than discovering it later.
Architects and architectural designers
We coordinate architecture in-house as part of the design and build contract. Where a project needs a conservation architect — usually a significant alteration to a listed building, or a scheme a local authority is resisting — we say so and we work alongside one rather than around them. If you already have an architect, we are content to build to their drawings.
Structural engineers
Any scheme removing or altering structure is designed and signed off by a structural engineer. On historic buildings this is not a formality: existing foundations, timber frames and masonry rarely match what a standard calculation assumes, and the engineer needs the building opened up and looked at rather than a drawing of it.
Heritage consultants
Where an application needs a Heritage Statement, or where the significance of a building has to be assessed and argued in writing, we bring in a heritage consultant. This is a specialist written discipline and we do not present ourselves as practitioners of it.
Conservation officers and Local Planning Authorities
We engage with the conservation officer and the planning authority on your behalf, and we prefer to do it early — a scheme discussed before submission is far more likely to be consented than one defended after refusal.
Specialist craftspeople
Masons, carpenters, plasterers and decorators experienced in traditional methods and materials, working as part of our team on the job rather than as a name on a list. Our subcontractor panel is set out on the About page.
Other specialists as a project requires
Surveyors, damp and timber specialists, and — where a barn or roof void is involved — an ecologist, because bat and nesting-bird constraints have stopped more barn conversions than planning officers have.
Why Mansouri Design & Build
The right team for heritage work.
Design-Led Thinking
Every heritage project begins with a considered design process — understanding the building's history, its character, and how a sensitive intervention can improve it without diminishing it.
Traditional Craftsmanship
We work with specialist masons, carpenters and decorators who understand lime, flint, oak and period materials — not tradespeople who have simply worked on old buildings.
Modern Construction Expertise
Heritage does not mean slow or expensive by default. We apply modern project management, procurement and construction management to heritage projects — delivering high standards efficiently.
Respect for Original Architecture
We do not impose our aesthetic onto historic buildings. Our job is to serve the architecture — to propose what is right for the building, not what is fashionable or convenient.
Complete Project Management
From initial surveys and planning applications through to the final finish — one team, one contract, one point of contact. No gaps between the design and the build.
Heritage questions
What owners of listed and period properties ask us.
- Can you extend a listed building?
- Often, yes — but the design has to earn it, and what is achievable varies enormously between two listed buildings of the same age. What generally succeeds is an addition that is subordinate to the host building, clearly of its own time rather than a pastiche, reversible where possible, and attached at a point where it does least harm to the historic fabric. What generally fails is a large addition on a principal elevation. The only way to know for your property is a survey and an early conversation with the conservation officer.
- Do I need listed building consent as well as planning permission?
- They are separate and you may need both. Planning permission deals with the development; listed building consent deals with the effect on the building's special character, and it applies to internal work that needs no planning permission at all. Permitted Development rights do not help you: they are removed on listed buildings.
- My house is not listed, but it is in a conservation area. What changes?
- The council takes a view on how the work reads from the public realm, so materials, window design, roof form and boundary treatment come under closer scrutiny, and demolition and tree work are separately controlled. Some Permitted Development rights may also have been withdrawn by an Article 4 direction — that varies street by street, so it has to be checked for your address rather than assumed from your neighbour's experience.
- Why can't we just use ordinary mortar and plaster? It is cheaper.
- On a solid wall it is cheaper once and more expensive afterwards. Cement mortar is harder than most historic brick, so moisture that would have left through a lime joint leaves through the face of the brick instead and the face spalls off — and a spalled brick face cannot be put back. Gypsum plaster on a solid wall traps moisture in the same way and the damp reappears further along. We have taken failed plaster off a period drawing room that was suffering exactly this, and the repair only held once the cause outside had been dealt with and the wall replastered in lime.
- Are you accredited for conservation work?
- No, and we will not imply otherwise. We are not currently members of a trade accreditation scheme and we hold no conservation accreditation. What we do have is completed heritage work with photography and written scopes, an insurance position including £1M professional indemnity, and references from the owners of the buildings. Our Standards page sets out what we do and do not claim.
- How much longer does heritage work take?
- Longer at the consent stage, and less predictable on site. Listed building and conservation area applications typically take longer than a householder application, and older buildings hide things — rotten wall plates, failed drainage, foundations that are not what the drawing assumed. We would rather tell you that at the start than in week six. Where a programme can be protected, it is usually by starting the consent process as early as the design allows.
- Will you work to my architect's drawings?
- Yes. A good many heritage projects arrive with drawings and a consent already in place, and we are happy to price and build them. Where we think a detail will cause a problem on site we will say so before we start rather than discover it halfway through.
- Do you work outside Essex?
- Yes — across Essex, Suffolk and London, which is where our completed work is. We would rather be honest that our heritage portfolio is concentrated in Essex, because that is where the majority of these buildings and the craftspeople we work with are.
More general questions on planning, cost and programme are answered on the FAQs page, and what we do and do not claim is set out on Our Standards.
Fully insured for heritage and listed building work.
£10M Employers Liability · £3M Public Liability · £1M Professional Indemnity. Certificates available on request.
Tell us about your heritage property.
Whether you're planning a listed building alteration, a sympathetic extension or a sensitive interior renovation — we'd like to hear about it. We respond within 24 hours.
We carry £10M Employers Liability · £3M Public Liability · £1M Professional Indemnity