Where we start
More space is only valuable when it works
Most residential projects start with one question: how much extra floor area can we get? We start with a different one: how should the house work?
The largest possible extension can darken the original rooms and leave the new space without a clear purpose. A fully open-plan layout can look good on a drawing but leave a family with one oversized room, poor acoustics, limited storage and nowhere quiet to go.
Our designs balance additional floor area with natural light, privacy, storage, movement through the house and the character of the existing building. Every square metre should earn its place.
Architectural services
we provide
Home extensions
We design rear, side-return, wraparound and double-storey extensions as part of the whole house: where daylight will reach, how people will move through the property and how the new space meets the garden.
Loft conversions
Dormer, mansard, hip-to-gable and rooflight conversions depend on more than fitting rooms under the roof. Stair position, headroom, structure, daylight and the effect on the floor below all have to work together.
New build homes
We design new build homes around their site, planning context, budget and occupants, with structural input from the concept stage so the design stays buildable.
Shown: Isleworth development visualisation
Whole-home remodelling
Some houses already have enough space but use it poorly. Before recommending construction, we test whether moving walls, doors, stairs or room functions would give a better result.
Shown: Mill Street, Luton
Technical drawings
Turn design intent into construction information. Building regulation drawings and details coordinated for the next stage, developed alongside the relevant structural information.
Prepared properly
MCIAT-qualified professionals
Your package is developed by people trained to turn design intent into technical information.
A clear programme
Typically 5–10 working days
Once the required information is available, we confirm the programme and keep the package moving.
Fewer gaps on site
One coordinated package
Architecture, structure and building services are considered together—not left for your builder to untangle.
How we work
How we approach residential design
Does it suit the property?
A Victorian terrace, an Edwardian semi and a contemporary building need different approaches. We review the building’s age, construction, original features and previous alterations, together with its planning history, neighbouring approvals and local constraints.
Does it suit the household?
We consider how you live now and how that may change. Where does the family come together? Where is privacy needed? What needs storing? Does a separate reception room or study still have value?
Can it be built properly?
Structure, party wall interfaces and construction implications are considered while the design can still change. This reduces the risk of finding out later that a key opening needs an intrusive beam or a ceiling has to drop.
Real project evidence
When we advise building less
The Better Home, Not the Largest Application
Our role is not to agree with every initial idea. We may recommend a smaller extension or a different internal arrangement where a larger addition would leave the original rooms too dark or remove too much garden, where the construction cost is out of proportion to the benefit, where the planning risk outweighs the extra space, or where internal reconfiguration would improve the house more effectively.
At Quarrendon Street, described below, an earlier design direction had already maximised floor area, but it produced a largely open interior with little privacy, storage or hierarchy. The improvement came from reorganising the layout, not from the floor area itself.
The best design is the one that produces the better home, not necessarily the largest planning application.
Why Floor Plans Alone Are Not Enough
A plan can look resolved while hiding problems. It won’t show restricted headroom, deep beams, ceiling voids, changes in level or how an extension meets the original house vertically.
Sections show height and volume. Structural input establishes how openings are supported. Party wall knowledge shows how the proposal meets the neighbouring building.
CLIENT FEEDBACK
Loved by homeowners and builders.Trusted across every detail.
“Excellent service! Very professional and punctual . Competitive price.”
“We used AC Design Solution for planning permission on a single storey extension and loft conversion, plus the building regulation drawings, structural calculations, and party wall surveying. They handled the whole process well and kept us updated throughout, which made things a lot less stressful than we expected. The drawings and structural work were solid, and the party wall side went smoothly too. Would recommend them to anyone needing help with planning and building regs.”
“I had an issue on site that required appointing a Party Wall Surveyor. My architect recommended Zubear from AC Design Solution, who I must say is extremely experienced and kept me updated throughout. We faced a challenging experience with the council and their surveyor, but Zubear overcame the issues, allowing me to get my Party Wall matters sorted out.”
“AC Design Solutions were fantastic in getting the job done promptly and in a professional manner. They also gave us helpful advice which assisted in our decision making with other aspects of the building works. I would highly recommend them.”
“Very supportive and helpful. Very fast response as well! Highly recommend”
Different buildings.
The same attention.
Selected projects
Your project
Recent projects
Two-storey extension on a corner plot
At 40 Wrottesley Road, a semi-detached house on the corner of Odessa Road, the proposals comprised a two-storey side and rear extension, a single-storey rear extension, a hip-to-gable roof extension, a rear dormer and two front rooflights.
The side extension replaces an old attached garage. Brent accepted the loss of the garage under Local Plan Policy BT2 and did not treat it as a parking issue.
The hip-to-gable conversion needed a specific argument. The original house had a hipped roof, and local policy was silent on converting it. We addressed this in the planning statement, showing that gable ends were an established feature of the street.
Brent granted planning application 26/0882 under delegated authority on 3 July 2026.
From 200 to 300 square metres in Fulham
At 48 Quarrendon Street, a Victorian terrace, the client wanted the accommodation expected of a substantial family home. The proposed design increases the gross internal area from about 200 to about 300 square metres.
An earlier direction had produced a largely open interior with plenty of floor area but little privacy, storage or hierarchy. We replaced it with a separate reception room, practical entrance, boot room and pantry, a substantial kitchen and dining space, basement family and wellness accommodation with a gym and sauna, and a private principal bedroom suite with walk-in wardrobes.
The property is in the Studdridge Street Conservation Area and is subject to an Article 4 Direction and a Flood Zone 3 designation. The proposals were coordinated with planning policy, neighbouring amenity, structural design, flood mitigation and the practical requirements of basement construction.
When the council’s transport team asked for a more complete Construction Logistics Plan, we developed the vehicle routing, delivery controls, spoil removal, concrete-mixer tracking and pedestrian management needed on a constrained residential street.
Planning application P/2026/01419/HH is currently under consideration.
One team, clear responsibility
Layout affects structure. Structural requirements affect openings and ceilings. Extensions, lofts and basements can trigger party wall obligations. When these services sit with unrelated firms, drawings conflict and responsibility becomes unclear.
At ACDS, architectural design, structural engineering, building regulation drawings and party wall surveying are coordinated by one accountable team. They remain separate professional stages and may need separate appointments.
We are not competing to be the cheapest drawing provider. A low initial fee is poor value if important questions are left until after submission or on site.
How it works
How your project progresses
The scope of work for a typical appointment can include the feasibility assessment, measured survey, existing and proposed floor plans, elevations, sections, site and location plans, two design meetings, two rounds of revisions, submission of the application and communication with the planning officer.
Three-dimensional views, planning statements and supporting reports can be added by agreement. Structural calculations, drainage design, building regulation drawings, application fees and specialist reports are separate unless expressly included.
Feasibility assessment
A desktop review of planning history, neighbouring development, conservation restrictions, flood risk and the local pattern of development.
Measured survey
Once appointed, we visit and measure the property and record its character, construction and relationship with its neighbours.
Concept design
Normally ready within 10 working days of the survey, developed from your brief and the constraints identified at feasibility.
Design review
Two online design meetings and two rounds of revisions to test the layout and refine it.
Planning submission
We prepare the architectural drawings, submit the application to the local authority and deal with the planning officer through to a decision.
Technical development
After planning approval, we can prepare the technical drawings and building regulation drawings for submission to Building Control, coordinate the structural engineering and provide project management or construction-stage support.
What a typical appointment includes
The scope of work for a typical appointment can include the feasibility assessment, measured survey, existing and proposed floor plans, elevations, sections, site and location plans, two design meetings, two rounds of revisions, submission of the application and communication with the planning officer.
Three-dimensional views, planning statements and supporting reports can be added by agreement. Structural calculations, drainage design, building regulation drawings, application fees and specialist reports are separate unless expressly included.
Areas we cover
We work throughout Greater London and generally within about 20 miles of it, including Slough, Maidenhead and parts of Berkshire, Buckinghamshire, Surrey and Hertfordshire. Larger projects further afield may be considered.
Common questions
Frequently asked questions
How long does planning permission take?
Householder applications are normally targeted for determination within eight weeks of validation. Amendments, consultation issues, requests for additional information and agreed extensions of time can make the process longer.
Do I need planning permission, or is it permitted development?
Many rear extensions and loft conversions can proceed as permitted development within set limits. Conservation areas, Article 4 Directions and previous alterations can remove or restrict those rights. We check this at the initial assessment, and where permitted development applies we normally recommend a Lawful Development Certificate.
Do I need an architect for my project?
Not necessarily. “Architect” is a protected title that can only be used by professionals registered with the Architects Registration Board (ARB); membership of the Royal Institute of British Architects (RIBA) is separate. Chartered Architectural Technologists are members of the Chartered Institute of Architectural Technologists and can provide design services and lead projects from inception to completion. What matters for your project is that the design process is led by a qualified professional with relevant experience.
Will you produce several design options?
Yes, where there are genuinely different ways to approach the property. We don’t produce superficial alternatives to fill a drawing set.
Are structural calculations included?
Structural engineering is a separate service and fee, delivered and coordinated by ACDS.
Can you guarantee planning permission?
No designer can. We research the property, policy and local precedent so the application is reasoned and properly presented.
Get started
Understand what your property could become
Tell us what you want to achieve. We’ll consider the property, its planning context and its practical constraints before recommending the right route.
Continue your research
Architectural design guide
Office to Hotel Conversion: Planning Permission, Change of Use & Building Regulations
Converting an office into a hotel requires planning approval, Building Regulations, fire safety, and structural upgrades. AC Design Solution has experience delivering such projects, including an 87-bedroom hotel conversion in Luton.
Can You Add Another Storey to an Existing Building? Planning Permission, Prior Approval & Structural Design
Extending a building upward can create valuable additional space without increasing its footprint. Depending on the property type and proposed use, the project may qualify for permitted development with prior approval or require full planning permission, alongside a detailed structural assessment.
How to Discharge Planning Conditions Before Construction Starts
Planning permission does not always mean construction can begin immediately. Pre-commencement conditions may require additional information or approvals, and these conditions must be discharged before work can lawfully start.
Can You Add Another Floor to an Existing Building? Planning, Structure & Building Regulations
Adding another floor can unlock valuable space without expanding a building’s footprint. But upward extensions involve more than just construction, from planning and structural capacity to access, fire safety and Building Regulations.
Can You Build an Extension and Loft Conversion at the Same Time?
Can you combine a house extension and loft conversion into one project? Yes – and in many cases, designing both together can be more practical and cost-effective. However, combining the work also means planning the project as one coordinated alteration rather than treating the extension and loft conversion as two separate jobs.
Loft Conversion Building Regulations in England: Structure, Fire Safety & Planning
Everything you need to know about loft conversion building regulations in 2026 — structural requirements, fire safety, planning rules and what drawings you need.