GSB BUILDING LIMITED
London-based private construction firm delivering full house refurbishments, extensions, basement/loft conversions, bespoke joinery and heritage restoration directly to high-net-worth residential property owners across prime central London postcodes.
- Company typePrivate
- Founded-
- HeadquartersLondon, United Kingdom
- Headcount1–10
- GTM typeB2C
- OfferingServices
What GSB BUILDING LIMITED does
GSB Building Ltd is a London-based, privately-held construction company specializing in high-end residential refurbishment, new-build and heritage restoration projects for high-net-worth property owners. Service offerings span the full project lifecycle, including full house refurbishments, side and rear extensions, basement and loft conversions, structural works (steel installation, propping), bespoke timber joinery, bathroom and kitchen installation with imported materials, structural glazing and replacement windows, and mechanical and electrical systems including AV integration and underfloor heating. The firm markets particular expertise in technically demanding assignments, including listed and heritage properties, and positions itself as a single-vendor solution that personally manages each project from design to completion.
The company's delivery model is direct-to-consumer, with project-based revenue earned through one-time construction fees quoted per scope. It maintains close working relationships with private clients, architects (named partners include Kibre and MMM Architects), surveyors, interior designers and specialist craftsmen, drawing on a curated network of sub-contractors. Operations are concentrated in central London's prime residential postcodes — SW1, SW3, SW5, SW7, SW11, SW18, W2, W8, NW3 — with a cumulative portfolio of more than 35 completed projects.
The firm operates as a small core team (6 listed employees) supported by an extended specialist sub-contractor network, and ships output primarily through this project-led, referral-driven engine. Marketing relies on a professional portfolio website and earned media in lifestyle publications (House & Garden 2015, Evening Standard 2016, Nappy Valley 2019, House Beautiful 2019) targeting HNW residential audiences in London. No public revenue, funding or ownership disclosures are available.
GSB BUILDING LIMITED firmographics
Firmographics- Name
- GSB BUILDING LIMITED
- Legal name
- GSB Building Ltd
- Website
- https://gsb-building.co.uk
- Company type
- Private
- Operating status
- Operating
- Headcount range
- 1–10 employees
- Short description
- London-based private construction firm delivering full house refurbishments, extensions, basement/loft conversions, bespoke joinery and heritage restoration directly to high-net-worth residential property owners across prime central London postcodes.
- Ownership category
- akta.pro rank
GSB BUILDING LIMITED industry classification
Industry- Product category
- Residential Construction Services
- NAICS
- Residential Remodelers (236118)
- SIC
- General Bldg Contractors - Residential Bldgs (1520)
- akta.pro primary industry
- Residential Design-Build & Renovation-Integrated Builders (IMAFABAE)
- akta.pro secondary industries
- Residential Interior Fit-Out (Multi-Family & High-End) (IMAFANAE), Architectural Glazing & Fenestration (Curtain Wall, Windows, Storefronts, Skylights) (IMAFAMAC)
Keywords
Where GSB BUILDING LIMITED is headquartered
LocationHeadquarters
- HQ city
- London
- HQ country
- United Kingdom
- HQ region
- Europe
Offices1 record
Markets served
GSB BUILDING LIMITED business model
Business model- GTM type
- B2C
- Offering type
- Services
- Cost components
- Personnel, Operations, Supply Chain, Marketing or Sales, Others
Revenue model
- Construction and Refurbishment Services: Project-based construction services for high-end residential properties including new builds, full refurbishments, extensions, and conversions. Revenue is generated through one-time project fees based on scope, specifications, and duration.
Go-to-market motion1 record
Distribution channels1 record
Marketing channels2 records
GSB BUILDING LIMITED product offering
Product offeringCore offering
GSB Building Ltd is a London-based construction company offering high-end residential refurbishment, extensions, basement and loft conversions, bespoke timber joinery, structural works, bathroom and kitchen installations, structural glazing, and mechanical and electrical (M&E) system design for private homeowners in prime London postcodes. The firm specializes in technically demanding projects including listed and heritage buildings, delivering premium finishes such as book-matched marble, tadelakt plastering, custom joinery, and integrated AV and lighting systems, with services managed end-to-end from initial brief through final handover.
Product overview
GSB Building Ltd is a London-based construction company offering a unified suite of construction and refurbishment services for high-end residential properties. Their core offering comprises full house refurbishments, home extensions, basement and loft conversions, bespoke joinery, structural works, bathroom and kitchen installation, and M&E systems. They work closely with architects and clients, managing projects from planning through to final finish. The company specializes in technically demanding projects including listed buildings and heritage properties, delivering bespoke finishes such as marble installation, tadelakt plastering, and custom timber joinery.
Differentiator
Problem solved
Functional benefit
Products and services
- Full House Refurbishments
- Side and Rear Home Extensions
- Basements and Lofts Conversions
- Carpentry and Bespoke Timber Joinery In-house bespoke joinery services including custom kitchens, wardrobes, doors, skirting, architraves, and panel molding, delivered for private residential clients.
- Structural Works Complex structural engineering including steel installation, propping, and structural modifications to create open spaces in residential properties.
- Bathroom and Kitchen Installation Complete bathroom and kitchen fitting services with imported materials and high-end finishes including marble installation, for private residential clients.
- Structural Glazing, Balconies, Handrails and Replacement Windows Installation of structural glazing systems, balconies, handrails, and window replacement including secondary glazing, for residential properties.
- Mechanical and Electrical (M&E) Systems Comprehensive M&E system design and installation including underfloor heating, air conditioning, and AV systems, for residential properties.
- Listed and Heritage Building Restoration Specialized expertise in restoring and preserving listed and heritage buildings, maintaining historical integrity while upgrading for modern use, for owners of period and listed residential properties in London.
Quantifiable outcome
- Projects delivered on time and within budget
- +1 more outcomes
Companies that use GSB BUILDING LIMITED
Customer profileSegments2 records
Ideal customer profiles2 records
GSB BUILDING LIMITED technology and API
TechnologyTechnology focussed No
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature3 records
GSB BUILDING LIMITED partnerships and signals
Strategic signalScale indicators1 record
Recent moves4 records
Expansion highlights4 records
GSB BUILDING LIMITED competitors and assessment
Company assessmentRegional players
- Plus Rooms: London specialist in basement and loft conversions, directly comparable on one of GSB's core service lines (basements and lofts) for the same HNW homeowner segment.
- Simply Lofts: London loft conversion specialist operating in the same prime-residential geography as GSB with partial overlap on conversions and interior fit-out services.
Direct peers
- Cube Construction: London luxury residential refurbishment contractor delivering full house renovations, extensions, and basement conversions for private clients in similar prime postcodes to GSB.
- Kisiel Group: London-based high-end residential construction and refurbishment contractor serving HNW clients in prime postcodes. Closest direct competitor to GSB in terms of segment, service mix, and craft-led positioning.
- Crystal Builders: London-based residential construction and refurbishment contractor delivering high-end home renovations, extensions, and bespoke finishes for private clients in comparable postcodes.
- Rendu Construction: Boutique London residential contractor specializing in high-end refurbishments and bespoke construction for private clients, with similar project-led, craft-led positioning.
- McGovern Construction: Bespoke residential construction and refurbishment specialist operating in London's prime market, with comparable focus on heritage properties, basements, and architect-led high-end finishes.
- Bennett Construction London: High-end residential construction firm in London offering refurbishments, extensions, and bespoke joinery, overlapping materially with GSB's core service set and client profile.
- Hurst Group: Construction and refurbishment company working across London's prime residential market with comparable craft-led positioning and high-end private client base.
Broad incumbents
- Octagon Developments: Established luxury residential developer in London and the Home Counties delivering large-scale prime residential projects; broader portfolio than GSB but overlapping client and postcode footprint.
Market position
Strengths4 records
Weaknesses4 records
Competitive moat3 records
Key risks6 records
Key highlights6 records
Customer concentration
GSB BUILDING LIMITED social profiles
Digital presenceGSB BUILDING LIMITED financial estimates
Financial estimateRevenue estimate
Valuation estimate
GSB BUILDING LIMITED leadership team
Management profileNumber of profiles
Profiles1 record
GSB BUILDING LIMITED funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
GSB BUILDING LIMITED M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about GSB BUILDING LIMITED
What does GSB BUILDING LIMITED do?
GSB Building Ltd is a London-based construction company offering high-end residential refurbishment, extensions, basement and loft conversions, bespoke timber joinery, structural works, bathroom and kitchen installations, structural glazing, and mechanical and electrical (M&E) system design for private homeowners in prime London postcodes. The firm specializes in technically demanding projects including listed and heritage buildings, delivering premium finishes such as book-matched marble, tadelakt plastering, custom joinery, and integrated AV and lighting systems, with services managed end-to-end from initial brief through final handover.
Is GSB BUILDING LIMITED a public or private company?
GSB BUILDING LIMITED is a private company. It is classified as unknown and is currently operating.
When was GSB BUILDING LIMITED founded?
GSB BUILDING LIMITED was founded in -1. It employs 1 to 10 people.
Where is GSB BUILDING LIMITED based?
GSB BUILDING LIMITED is headquartered in London, United Kingdom, in the Europe region.
How does GSB BUILDING LIMITED make money?
One revenue line is on record: construction and Refurbishment Services.
Who are GSB BUILDING LIMITED's main competitors?
Regional players on record are Plus Rooms and Simply Lofts. Direct peers are Cube Construction, Kisiel Group, Crystal Builders, Rendu Construction, McGovern Construction, Bennett Construction London and Hurst Group. Octagon Developments is listed as a broad incumbent.
Does GSB BUILDING LIMITED have an API?
No public API is recorded for GSB BUILDING LIMITED.
What industry is GSB BUILDING LIMITED in?
GSB BUILDING LIMITED's product category is Residential Construction Services. Its primary akta.pro industry code is IMAFABAE, Residential Design-Build & Renovation-Integrated Builders, with a secondary code of IMAFANAE, Residential Interior Fit-Out (Multi-Family & High-End). Its NAICS code is 236118 and its SIC code is 1520.