House Extensions & Loft Conversions in St Albans
Conservation area expertise for St Albans' period properties. Award-winning design & build from Finchley N3 — architecture, planning, construction & project management under one roof.
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200+ Reviews
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LABC Partners
Award-Winning Design & Build in St Albans
St Albans is a city of exceptional architectural character. From the medieval streets around the Cathedral and Verulamium Park to the handsome Victorian and Edwardian terraces of the city centre, the distinctive 1930s housing of Marshalswick, and the substantial villas of Clarence Park — this is a place where design quality and planning sensitivity are not optional. They are essential.
LCCL Construction serves St Albans, London Colney, Park Street and Wheathampstead from our base in Finchley N3.
Why St Albans Homeowners Choose LCCL
We have been working across Hertfordshire for over 20 years, and we understand why St Albans requires a different approach from standard suburban building work. The city’s extensive conservation area coverage, its wealth of period properties, and St Albans District Council’s well-established conservation team all demand architects who know the local planning landscape and builders who can deliver the quality that these properties deserve. With LCCL, you get both in one company.
Architecture, structural engineering, planning, construction and project management — all handled by one team under one comprehensive quote. No separate architect to hire. No subcontractors. No surprises.
LABC Building Excellence Award Winners 2024 — Independent industry recognition that our work meets the highest national standards.
Conservation Area Expertise — Our architects have experience designing extensions and conversions within St Albans’ multiple conservation areas, working with the district council’s conservation team.
200+ Reviews Averaging 4.7/5 — Real homeowners across Hertfordshire and London.
Complete Design & Build — Architecture, structural engineering, planning, construction, project management, building control and 10-year LABC warranty. One quote. No extras.
Our Services
Design and build under one roof, Architecture, planning, construction, and finishing — managed by one team, from start to finish.
- HOUSE EXTENSIONS
House Extensions in St Albans
St Albans’ high property values make extensions an excellent investment. The cost difference between a three-bed and a four-bed Victorian terrace in the city centre can be £150,000 or more — plus stamp duty. A well-designed extension delivers the additional space for significantly less, without the upheaval of moving.
The challenge in St Albans is designing extensions that satisfy the conservation team while creating genuinely modern living spaces. That is exactly what LCCL’s in-house architects do.
Extension Types for St Albans Properties
Period-Sensitive Rear Extensions — The most common project in central St Albans. For properties within conservation areas, the extension design must use appropriate materials and proportions. Our architects understand what the conservation team expects to see. Costs: £55,000 to £100,000.
Single-Storey Rear Extensions — Popular across Marshalswick, Fleetville and areas outside conservation areas. Standard PD allows 6 metres (detached) or 4 metres (semi/terrace). Kitchen-diners opening to the garden. Costs: £50,000 to £85,000.
Double-Storey Extensions — Popular in Marshalswick and Fleetville where growing families want both space and bedrooms. Conservation area properties need planning permission for double-storey work. Costs: £95,000 to £175,000.
Orangeries — The larger properties in Clarence Park, Jersey Farm and Wheathampstead suit orangery-style extensions that create light-filled rooms connecting house and garden. Costs from £40,000.
What Is Included in Every Extension Quote
All prices include: in-house architectural design, structural engineering, planning applications to St Albans District Council including conservation area submissions where required, all construction, project management, building control via LABC, and a 10-year LABC warranty. No hidden extras. Call 020 8037 7332.
- LOFT CONVERSIONS
Loft Conversions in St Albans
St Albans’ housing stock offers excellent loft conversion potential across all its distinct character areas. The Victorian and Edwardian terraces in the city centre have steeply pitched roofs with generous ridge heights. The 1930s semis of Marshalswick and Fleetville have hipped roofs ideal for hip-to-gable conversions. The larger detached homes across the AL postcodes often have enough roof space for two-bedroom conversions.
Within St Albans’ many conservation areas, loft conversion design must respect the existing roofscape. Front-facing dormers are generally unacceptable. Rear dormers and mansard conversions are usually achievable with appropriate design — but applications must demonstrate sensitivity to the period character. Our architects handle this routinely.
Loft Conversion Types for St Albans
Rear Dormer Conversions — The most versatile option and the one that works best in conservation areas, keeping all changes to the rear. Costs: £44,000 to £66,000.
Hip-to-Gable Conversions — Ideal for the 1930s semis in Marshalswick, Fleetville and New Greens. Combined with a rear dormer for maximum space. Costs: £48,000 to £70,000.
Mansard Conversions — Premium option creating maximum headroom. Well suited to the Victorian terraces of the city centre where the roof pitch allows for an elegant mansard profile. Always requires planning. Costs from £62,000.
Velux and Rooflight Conversions — Where conservation area restrictions limit external roof alterations, a conversion using heritage-style rooflights preserves the existing roof profile entirely. Often the simplest planning route in the most sensitive areas. Costs: £32,000 to £50,000.
What Is Included in Every Loft Quote
All prices include: in-house architectural design, conservation area planning applications where needed, structural engineering, scaffolding, all construction, staircase, insulation, electrics, plumbing for en-suite, building control via LABC, project management, and 10-year LABC warranty. No hidden extras. Call 020 8037 7332.
- RENOVATIONS
Renovations in St Albans
St Albans has a wealth of period properties that reward sympathetic renovation. The Victorian terraces in the city centre often have original features — cornicing, ceiling roses, fireplaces, timber panelling, encaustic tile floors — that deserve preservation and restoration rather than removal. At the same time, the kitchens, bathrooms and building services in these homes usually need comprehensive upgrading.
The skill of renovating a St Albans period property is knowing what to keep and what to replace. LCCL’s experience with period properties across Hertfordshire and North London means we get this balance right.
Across Marshalswick and Fleetville, the 1930s and interwar housing typically needs less period sensitivity but benefits from comprehensive modernisation — rewiring, replumbing, new heating systems, kitchen and bathroom replacement, and opening up ground floors by removing internal walls. The larger properties in Clarence Park sometimes need full refurbishments that address every aspect of the house from structure to finishes.
Typical costs in St Albans: kitchen renovation £25,000 to £55,000, bathroom £12,000 to £25,000, sash window refurbishment £500 to £1,200 per window, full refurbishment from £80,000. Detailed quotes provided. Final costs confirmed once designs and structural requirements are agreed.
- ARCHITECTURE
In-House Architecture in St Albans
St Albans has more conservation area coverage than almost any other city in Hertfordshire, and the district council’s conservation team is experienced, thorough and expects high-quality submissions. An architect unfamiliar with St Albans’ planning landscape will underestimate the level of design documentation required and the sensitivity expected in conservation area applications. A rejected application wastes months and costs money.
LCCL’s in-house architects have worked on projects within St Albans’ conservation areas and understand what the council expects: heritage impact assessments that demonstrate genuine understanding of the local character, design and access statements that justify the approach, and drawings that show appropriate materials, proportions and detailing.
Our integrated design and build model means these designs are not just planning-compliant but buildable, within budget, and exactly what gets delivered on site. Every St Albans project includes: measured survey, concept designs, 3D visualisations, construction drawings, conservation area planning applications with full supporting documentation where required, structural engineering, and LABC building regulations. All included in your quote — no separate architect fees.
- LOCA PLANNING EXPERTISE
Planning & Local Knowledge — St Albans
Conservation Areas in St Albans
St Albans City Centre Conservation Area — Covers the historic core around the Cathedral, St Peter’s Street, George Street, Holywell Hill and surrounding streets. The most tightly controlled area. Fishpool Street Conservation Area — One of the most architecturally significant streets in Hertfordshire. Listed buildings predominate. Clarence Park Conservation Area — Substantial Victorian and Edwardian villas. Sopwell Conservation Area — Area around Sopwell Lane and ruins of Sopwell Priory.
Marshalswick Conservation Area — Parts of the distinctive 1930s to 1950s residential development. Fleetville Conservation Area — Parts of the Edwardian and interwar housing. Romeland Conservation Area — Around Romeland and Abbey Mill Lane. Bernard’s Heath Conservation Area — Around Bernard’s Heath and Camp Road.
Green Belt — Countryside surrounding St Albans is designated Metropolitan Green Belt, affecting properties on the edge of the built-up area and in villages. Extensions must not be disproportionate relative to the original dwelling.
Property Types
City Centre — Victorian and Edwardian terraces and semis with original features. Conservation area throughout. Marshalswick — Characterful 1930s to 1950s semis and detached houses on tree-lined streets, parts in conservation area. Fleetville — Edwardian and interwar terraces with good loft conversion potential. Clarence Park — Substantial Victorian and Edwardian villas, conservation area. Jersey Farm — 1970s and 1980s housing, generally outside conservation areas. London Colney — Mixed housing south of the city, some in Green Belt.
Typical Project Timescales
St Albans planning decisions: 8 to 10 weeks, sometimes longer for conservation area applications. Green Belt applications may also take longer. Loft conversions: 8 to 12 weeks on site. Extensions: 10 to 20 weeks. Design phase: 8 to 12 weeks.
Green Belt
Countryside surrounding St Albans is designated Metropolitan Green Belt, affecting properties on the edge of the built-up area and in surrounding villages. Extensions to existing dwellings must not be disproportionate relative to the original building. Our architects assess Green Belt implications and design within policy limits.
Typical Planning Timescales
St Albans planning decisions: 8 to 10 weeks, sometimes longer for conservation area applications. Green Belt applications may also take longer. LDCs: approximately 8 weeks. Building control: inspections throughout construction, final sign-off at completion.
Building Control
All LCCL projects are managed through LABC building control. Inspections at each key stage ensure compliance with Building Regulations. At completion, you receive a building control completion certificate and optional 10-year LABC warranty.
Frequently Asked Questions
How much does a house extension cost in St Albans?
Period-sensitive rear extensions in conservation areas: £55,000 to £100,000. Standard rear extensions outside conservation areas: £50,000 to £85,000. Double-storey extensions: £95,000 to £175,000. Orangeries: from £40,000. All prices include architecture, structural engineering, planning applications to St Albans District Council, construction, project management, and 10-year LABC warranty.
Is my St Albans property in a conservation area?
St Albans has extensive conservation area coverage including the City Centre, Fishpool Street, Verulam Road, Bernard’s Heath, Clarence Park, Marshalswick, and others. Many properties fall within these areas. Our architects check your specific address and advise on what restrictions apply. Conservation area projects require sympathetic design with appropriate materials — this is what our in-house architects specialise in.
Do I need planning permission for a loft conversion in St Albans?
Outside conservation areas, most loft conversions qualify under permitted development. Within conservation areas, rear dormers may need planning permission, and front-facing dormers are generally unacceptable. Mansard conversions always need permission. Our architects assess your property and handle all necessary applications to St Albans District Council.
What loft conversions suit St Albans properties?
Victorian and Edwardian terraces in the city centre have steep roofs ideal for rear dormers. 1930s semis in Marshalswick and Fleetville suit hip-to-gable conversions. Larger detached homes across the AL postcodes can accommodate two-bedroom conversions. We assess your roof space and recommend the best type.
How long does a building project take in St Albans?
Loft conversions: 8 to 12 weeks. Single-storey extensions: 10 to 14 weeks. Double-storey: 14 to 20 weeks. Conservation area planning applications typically take 8 weeks. Add 8 to 12 weeks for design and engineering before construction starts. Full timeline included with every quote.
Areas We Cover
Based in Finchley N3, serving London and Hertfordshire.
North London and Hertfordshire
Barnet | Finchley | Hendon | Muswell Hill | Edgware | Enfield | Borehamwood | Potters Bar | Watford | St Albans
Across London
Hampstead | St Johns Wood | Islington | Kensington & Chelsea | Fulham | Clapham | Richmond | Putney & Wandsworth | Crouch End | Stoke Newington | Highgate | Ealing | Notting Hill | Camden | Queens Park