Business Details
11 Years
experience
Expert Residential Architects in Hampton, London
Square One Architects is a RIBA Chartered Practice established in 2015, founded by ARB and RIBA Chartered Architect Iacopo Sassi. Based in Hampton, South West London, we specialise in bespoke residential architecture, delivering high-end projects including extensions, loft conversions, and full home renovations. With over 15 years of professional experience, our team excels in creating functional, sustainable living spaces that harmonise with clients' lifestyles. We prioritise natural light integration and meticulous design, achieving planning approval for over 100 projects since our inception.Our expertise extends to lighting design, conservation areas, and navigating complex planning processes across Greater London. Featured in RIBA publications and Houzz, we maintain strong relationships with local authorities and industry professionals to ensure seamless project delivery. Our collaborative approach combines technical precision with creative vision, offering end-to-end support from feasibility studies to construction completion.
Services
Residential Architecture
Loft Conversions
Home Extensions
Interior Design
Lighting Design
Conservation Projects
Planning Applications
Landscape Design
Details
- Year established: 2015
Highlights and features
- 15+ years of residential architecture expertise in South West London
- RIBA Chartered Practice with proven planning application success
- Specialists in natural light optimisation and energy-efficient design
- Award-winning designs featured in RIBA and Houzz publications
- Comprehensive service from concept to construction completion
Associations and certifications
- RIBA
- ARB
What people say
Excellent service
Transformed our home
Detailed planning expertise
Creative solutions
Professional throughout
Services
Residential Architecture
Our residential architecture service creates tailored living spaces that balance aesthetic appeal with functional requirements. We specialise in new builds, renovations, and property transformations across London and Surrey. Our RIBA Chartered team combines technical expertise with creative vision to deliver projects that enhance property value and quality of life. Each design prioritises natural light, spatial efficiency, and compliance with local planning regulations.
Loft Conversions
We transform underutilised loft spaces into valuable living areas while maintaining structural integrity and aesthetic harmony. Our designs maximise headroom and natural light through strategic dormer placements and rooflight integration. The service includes planning applications, structural calculations, and coordination with building control authorities. Clients benefit from increased property value and expanded living space without garden footprint reduction.
Home Extensions
Our home extension service creates seamless spatial expansions that complement existing architecture. We specialise in rear, side, and wrap-around extensions that enhance natural light and improve property functionality. The process includes feasibility studies, material selection, and planning permission acquisition. Each project maintains architectural coherence while addressing specific client lifestyle requirements through innovative spatial solutions.
Interior Design
We create cohesive interior environments that reflect client personalities while optimising spatial efficiency. Our service covers kitchen/bathroom design, lighting schemes, and bespoke joinery solutions. We coordinate material selections and finishes to ensure continuity between new extensions and existing structures. The approach integrates practical considerations with aesthetic elements to create functional, visually appealing living environments.
Planning Applications
We manage the complete planning application process for residential developments across London. Our expertise includes pre-application consultations, submission preparation, and negotiation with local authorities. We specialise in securing approvals for challenging projects in conservation areas and listed buildings. The service ensures compliance with local regulations while maintaining design integrity throughout the approval process.
People
Iacopo Sassi
Director
Iacopo Sassi is a RIBA and ARB Chartered Architect with 15+ years' experience in residential design. He founded Square One Architects in 2015 after working with leading practices including Foster+Partners. Specialising in South West London projects, he combines technical expertise with creative vision to deliver award-winning architectural solutions.
Questions
What architectural services do you specialise in?
We focus on residential architecture including extensions, loft conversions, full renovations, and new builds across South West London and Greater London.
Are you experienced with conservation areas?
Yes, we have extensive experience working in conservation areas, listed buildings, and locally listed properties across London.
How do you handle planning applications?
We manage the complete planning process, including pre-application advice, submissions, and securing approvals for complex projects.
Do you work outside South West London?
While based in Hampton, we work throughout Greater London and surrounding areas including Surrey and Kent.
What makes your practice different?
Our RIBA Chartered team combines technical precision with creative design, offering end-to-end service from concept to completion.
