Frequently Asked Questions

We serve South, Southwest, West and sometime Central London, with particular expertise in Wandsworth, Richmond, Merton and surrounding borough including conservation areas.

Andrew Catto Architects has been serving Londoners since 1999, with over 25 years of architectural expertise. We've successfully completed over 1,200 projects, from small extensions to major renovations, establishing ourselves as trusted experts in these areas.

Our directors Andrew Catto and Melissa Lawrence da Cunha bring extensive experience to every project. Andrew has 35+ years of architectural expertise, qualifying in 1976 and founding the practice in 1999. Melissa has 25+ years of international experience, joining as director in 2017. Together with our experienced team, we've built over 150+ trusted client relationships.

Our local knowledge covers planning regulations, building codes, and area-specific requirements for these prestigious London boroughs. We handle everything from initial concept design through to completion and handover.

We provide comprehensive architectural services including house extensions, loft conversions, basement developments, planning applications, building regulations, interior design, tender, and project management.

We love to. Knowing about cost control when developing informs on home projects too. What home owners tell us helps shape development people wants to live in.

Sites for these are rare but we do single houses see Lytton Grove, Weybridge, etc. Where there is an existing building on the land we can look at adapting or extending this instead. These are often adding character to the resulting house.

Yes, we offer comprehensive interior design services including space planning, material selection, bathrooms and kitches, lighting design, and furniture specification. We ensure the interior design works seamlessly with the architectural design for a cohesive result.

Yes, we can help with furniture selection, decoration, and styling to complete your project. We work with trusted suppliers and can coordinate the entire project from concept to final decoration including finding space for your treasured pieces.

Yes, we have extensive experience working in conservation areas and listed buidings. With our 95% planning success rate including complex sites, we understand the specific requirements and restrictions, ensuring our designs respect the character and heritage of these protected areas while meeting modern living needs.

Conservation areas have additional planning restrictions to preserve architectural character. This may affect materials, design details, and even the overall form of your extension. We have extensive experience working within these constraints and can design solutions that respect heritage while meeting modern needs.

Yes, we have experience working with listed buildings and understand the additional requirements and restrictions. Listed building consent is required for any alterations, and we work closely with conservation officers to identify and ensure our designs preserve the building's historic character.

Project timelines vary depending on complexity, size, and planning requirements. The process typically includes design development, planning and building regulations approval, and construction phases. We provide realistic timelines during our initial consultation and keep you informed throughout the process. If you want that kitchen for Christmas, hire us before Easter. New building takes longer, but the biggest delays come from changing your mind part way.

Planning permission typically takes 8-12 weeks for standard applications. Complex applications or those in conservation areas may take longer. With our 95% planning success rate including complex sites, we have extensive experience navigating the planning process and keep clients informed throughout.

Permitted Development allows certain building works without planning permission. This includes single-story rear extensions up to 4m for detached houses and 3m for other houses, loft conversions (expect in conservation areas) with specific volume limits, and some garage conversions. We can assess if your project qualifies.

Mostly, but not always it depends on the size, location, and type of extension. Single-story rear extensions under 4m (detached) or 3m (other) may fall under Permitted Development. We'll assess your specific project and guide you through the appropriate approval process.

Yes, subject to planning permission and building regulations. Garden rooms and extensions must comply with height restrictions, boundary setbacks, and overall plot coverage limits. We'll assess your garden's potential and design solutions that provide the best use of available garden space.

Building regulations ensure your project meets safety, energy efficiency, and accessibility standards. Even if you don't need planning permission, you'll likely need building regulations approval even for quite small works. We handle this process and ensure compliance with all requirements.

Our design process follows RIBA stages: 1) Brief development and site analysis, 2) Concept design and feasibility, 3) Developed design and planning application, 4) Technical design and building regulations, 5) Construction and handover. We involve clients at every stage. The brief is Key and where you imput is most important.

We carefully analyze your existing property's architectural style, materials, proportions, and character. Our designs complement and enhance your home while maintaining visual harmony. We use materials and details that respect the original design language.

Absolutely. We're Green Register and AECB member and committed to sustainable design and can specify eco-friendly materials, energy-efficient systems, and sustainable construction methods. This includes natural materials, high-performance insulation, and renewable energy integration where appropriate.

We design for energy efficiency from the start, including high-performance insulation, energy-efficient glazing, and sustainable heating systems. We can achieve high energy performance standards and help you to qualify for energy efficiency grants or incentives.

We work closely with clients to understand their budget from the start. With over 1,200+ completed projects and 150+ repeat clients, we've developed expertise in designing within budget parameters and suggesting cost-effective alternatives without compromising quality. We provide detailed cost estimates and help manage costs throughout the project.

Yes, we provide full project management services including contractor selection, site inspection, quality control, and progress monitoring and valuing work in progress required. We act as your representative throughout construction, ensuring the project meets your expectations and stays on schedule.

We have a network of trusted, vetted contractors with proven track records built up over 25+ years in practice. We select contractors based on their experience with similar projects, quality of work, reliability, and competitive pricing. With over 1,200+ completed projects, we've established strong relationships that ensure quality delivery. Or we can work with contractors you've already selected.

We're on-site regularly to identify and resolve issues early. We have established relationships with contractors and can quickly address any problems. Detailed documentation is key and regular communication ensure issues are resolved efficiently with minimal disruption.

Yes, we can work with your existing contractors or builders. We'll assess their capabilities and ensure they understand the project requirements. We can provide detailed drawings and specifications to help them deliver the project to our design standards.

We build realistic timelines into our project planning and maintain regular communication with contractors. If delays occur, we identify the cause and work with contractors to minimize impact. We keep clients informed and adjust schedules as needed.

Extension costs vary significantly based on size, complexity, materials, and finish quality. Costs can range widely depending on your specific requirements and design choices. We provide detailed cost estimates during the design process and work with you to achieve your goals within your budget.

Single-story rear extensions are typically most cost-effective, offering good value for money. Loft conversions also provide excellent value, creating additional living space without extending the building footprint. We'll assess your property and recommend the most cost-effective approach.

We're transparent about all costs from the start. Additional costs may include planning fees, building regulations fees, party wall agreements, and unexpected structural issues. We identify potential additional costs early and keep you informed throughout the process. But most buildings hide something you won't find until work starts. Even projects should have a contingency. But we often manage not to spend this.

Yes, well-designed extensions typically add significant value to your property. A quality extension often increases property value beyond the construction cost. We design with both lifestyle and investment value in mind, ensuring your extension is a sound financial decision that enhances your home and your quality of life. Refitting add little to the sales price, but you'll get the value of using it for years to come.

Putney and Wandsworth have specific planning requirements including conservation area restrictions, flood risk considerations, and local character preservation. We understand these requirements and design solutions that comply while maximizing your property's potential within local constraints. Most planning policies are very similar wherever you area, but we'll point out any loca quirks.

Common challenges include Victorian/Edwardian construction methods, party wall issues, basement water tables, and limited garden space. We're experienced in addressing these challenges and can design solutions that work with your property's specific characteristics.

Local authorities have specific requirements for parking and access, especially for larger extensions. We ensure our designs comply with these requirements and can suggest solutions that maintain or improve parking and access arrangements. Most London Councils now expect new buildings and conservation to be "car free"

We recommend materials that are durable, sustainable, and appropriate for your property type. This includes high-quality bricks, natural stone, sustainable timber, and modern insulation systems. We select materials based on your budget, design preferences, and local character requirements.

We consider acoustics in our designs, especially for extensions near busy roads or for music rooms. We can specify soundproofing materials and design solutions that minimize noise transmission and create comfortable living environments. Unlike in recent past modern flat conversions require effective soundproofing between flats.

We work with structural engineers to ensure all designs meet structural requirements. This includes foundation design, structural calculations, and ensuring compliance with building regulations. We never compromise on structural safety.

We assess existing drainage and utilities during the design process and ensure our designs work with or improve these systems. This may include upgrading drainage, repositioning utilities, or installing new systems as required.

We maintain regular communication throughout the project. We typically meet weekly during design phases and bi-weekly during construction. We're also available by phone and email for urgent questions and provide regular progress updates. Change at the initial design stage is simple, but changes late, particularly when on site, can cause delay, wasted work and extra cost. Most of the projects we hear about that run over time and over budget are the result of late changes.

We understand that requirements can evolve. We can accommodate design changes, though major changes may affect timeline and cost. We discuss the implications of any changes and ensure you're fully informed before proceeding.

Yes, we provide ongoing support after project completion. This includes addressing any issues that arise, providing maintenance guidance, and being available for future projects. We maintain long-term relationships with our clients.

Client satisfaction is our priority. We work closely with you throughout the project to ensure the result meets your expectations. If you have concerns, we address them immediately and work to resolve any issues to your satisfaction. We can't guarantee consent so if we suggest changes, it's for good reason.