Business Details
11 Years
experience
Award-Winning Residential Architects in Hampton, London
Established in 2015 by ARB and RIBA Chartered Architect Iacopo Sassi, Square One Architects is a RIBA Chartered Practice based in Hampton, South West London. Specialising in bespoke residential architecture, we deliver high-end projects including extensions, loft conversions, and full renovations. With over 15 years of professional experience, our team prioritises functional, sustainable design that maximises natural light and enhances well-being. Our expertise in navigating local planning authorities is evidenced by over 100 successful applications since our founding.We maintain strong relationships with local authorities and industry professionals, ensuring seamless project execution from concept to completion. Our work has been featured in publications such as Real Homes, Houzz, and RIBA journals. We serve Greater London and surrounding areas, with particular focus on South West London boroughs including Richmond, Kingston, and Wandsworth. Our commitment to detailed design and client collaboration has earned consistent five-star testimonials from satisfied homeowners.
Services
Residential Architecture
Loft Conversions
Extension Design
Planning Applications
Lighting Design
Conservation Projects
Interior Design
Landscape Design
Details
- Year established: 2015
Highlights and features
- 15+ years' experience in residential architecture with RIBA accreditation
- Proven success with 100+ planning applications since 2015
- Specialist expertise in natural light optimisation and sustainable design
- Award-winning practice featured in industry publications
- Comprehensive service from concept to construction completion
Associations and certifications
- Royal Institute of British Architects (RIBA)
What people say
Transformed the house completely
Excellent planning expertise
Detailed drawings and clear communication
Highly recommended by clients
Professional and reliable service
Services
Residential Architecture
Our residential architecture service focuses on creating tailored living spaces that combine functionality with aesthetic appeal. We specialise in extensions, renovations, and new builds across South West London. Our approach prioritises natural light optimisation and sustainable materials while maintaining strict adherence to planning regulations. Clients benefit from our extensive experience in managing projects from initial concept through to construction completion.
Loft Conversions
We transform underutilised loft spaces into valuable living areas while respecting property character and planning constraints. Our designs maximise headroom and natural light through strategic dormer placement and rooflight integration. We handle all aspects from structural calculations to final detailing, ensuring seamless integration with existing building fabric while delivering modern, functional spaces.
Extension Design
Our extension design service creates harmonious additions that enhance property functionality and value. We specialise in rear, side, and wraparound extensions that optimise garden connections and natural light. Each design balances contemporary elements with existing architectural character, particularly in conservation areas and listed buildings where sensitive material selection is crucial.
Planning Applications
We navigate complex planning processes for residential projects, leveraging our 90%+ approval rate since 2015. Our service includes pre-application consultations, detailed submission packages, and liaison with local authorities. We specialise in securing permissions for challenging sites including conservation areas through evidence-based design justifications and 3D visualisations.
Lighting Design
Integral to our residential projects is our specialist lighting design service. We optimise natural light through strategic window placement and rooflight integration while designing artificial lighting schemes that enhance spatial quality. Our approach combines technical precision with aesthetic considerations to create layered lighting solutions that improve both functionality and atmosphere in residential spaces.
People
Iacopo Sassi
Director
Iacopo Sassi established Square One Architects in 2015 after gaining extensive experience at leading practices including Foster+Partners. He specialises in residential architecture with a focus on light optimisation and spatial transformation. Holding both ARB and RIBA chartership, he combines technical expertise with creative vision to deliver bespoke solutions for private clients across London.
Questions
What architectural services do you specialise in?
We specialise in bespoke residential architecture including extensions, loft conversions, full renovations, and new builds across South West London.
Are you RIBA Chartered Architects?
Yes, we are a RIBA Chartered Practice with director Iacopo Sassi holding both ARB and RIBA chartership.
Do you handle planning applications?
Yes, we have secured over 100 planning approvals since 2015, including complex cases requiring pre-application negotiations.
Which areas do you cover?
We operate throughout Greater London with particular focus on Hampton, Kingston, Richmond, and surrounding South West London boroughs.
Can you assist with lighting design?
Yes, we have specialist expertise in natural and artificial lighting design as integral to our residential projects.
