Proposed garden view of a large bungalow extension in Lapworth, with two glazed gables flanking a central flat-roofed extension.

Architectural design for new homes, extensions, renovations & conversions

Whether you're planning a new home, converting a barn, or making the most of your existing house, I'll help you explore what's possible.

Together, we'll develop your ideas through conversation, sketches, and 3D design, then turn your choices into detailed architectural drawings.

McTernan Design | Architectural Design Studio serving Solihull, Birmingham, Warwickshire and the Cotswolds

Working directly with Mark McTernan on your residential project

Garden view of a single-storey kitchen and dining extension in Stratford-upon-Avon, with black-framed bifold doors, a glazed gable and adjoining flat roof.

I’m Mark McTernan, BA (Hons), MArch, an architectural designer working across Birmingham, the West Midlands, Warwickshire and the Cotswolds.

I work directly with homeowners, self-builders, landowners and small developers on residential projects. We begin by discussing what you want to change or build, then develop the proposal through sketches and 3D reviews.

You’ll review the proposal as it develops and discuss any changes directly with me. I remain your point of contact through the agreed planning and technical drawing stages.

Assessing residential design options for your property or site

Proposed front view of a house in Solihull showing a replacement garage with a master bedroom above, two dormer windows and a new pitched-roof entrance porch.

Tell me what you want to change or build, whether it is a new home, replacement dwelling, small housing development, barn conversion or alterations to an existing house.

I consider your accommodation needs alongside the existing building, site and surroundings. We discuss the options and the constraints that could affect them, including where the layout, scale or position of the proposal may need to change.

Street view of a bespoke replacement home in a Solihull conservation area, with a pale stone façade, black entrance gates and mature trees behind a boundary wall.

Architectural design for new homes, developments, extensions and conversions

New and replacement homes

Bespoke residential design developed around your site, accommodation requirements and architectural preferences, with 3D modelling throughout the design process.

3D interior view of a Warwickshire bungalow with an open-plan kitchen, dining and living area, two roof lanterns and large windows overlooking the countryside.

Small developments

For a small housing development, I consider access, parking, private gardens and the relationship between the homes as part of the site layout. These choices affect each building's position and how its accommodation can be arranged.

Proposed rear garden view of a bungalow in Solihull with a single-storey rear extension, loft conversion and raised patio.

House extensions & loft conversions

I consider the existing rooms alongside the additional space you want. The design may involve an extension, changes to doorways or stairs, or a revised layout within the house.
I'll lay out the different options and their implications so you can choose the one that best fits your needs.

I'll lay out the different options and their consequences so you can choose the one that best responds to your brief.

Proposed 3D view of a barn conversion in Bromsgrove, showing a family home in the open countryside with dark millboard cladding, reclaimed brickwork and large glazed openings.

Barn conversions

When converting a barn, the existing structure, roof, and opening positions affect where rooms can go; I think about how to include appropriate accommodation without losing the features that make the building worth converting.

Reviewing your proposed home in 3D before you agree to the design

Front view of a remodelled house in Dorridge, showing a contemporary three-storey extension with full-height gable glazing, brick-slip cladding and replacement windows.

I develop the drawings and 3D model together as the proposal takes shape. We use the model to review how the rooms connect, the routes through the home, and the views toward the garden, while we can still reconsider the layout.

Seeing the design and checking dimensions on screen

During a design review in your home, I normally show the working model on your television. You can ask me to return to a room, show another angle or explain why I have positioned an opening or stair where I have.

I can temporarily hide a roof, wall or floor to reveal the part we are discussing. In a loft conversion, this can show how the stair fits beneath the roof and the headroom at a particular point. I can show the relevant dimensions and explain what constrains its position.

At eye level, we can look through a proposed opening towards the garden or follow the route between existing and new rooms. We can compare an open-plan layout with spaces that retain some separation and discuss which arrangement suits how you want to use the home.

Exploring the proposed rooms in virtual reality

Optional VR lets you explore the proposed rooms from within, with a life-size sense of the space around you. You choose where to look and which parts of the model to explore. You can move through the spaces, look up at the vaulted ceiling, check you are happy with the position of the rooflights, or examine the space on the landing for potential storage spaces,

I guide you through using the headset, and its view also appears on the television. Your family can see what you are looking at and discuss it with you. If you want to reconsider part of the design, I can make those changes and update them on the VR goggles in front of you.

Your quotation sets out the modelling and review services, including any optional internal modelling and VR.

Solihull extension linking a window seat and patio seating

In the proposal I prepared to replace a conservatory in Solihull, I set back part of the back wall to create a patio seating area and a matching window seat inside, with a folding window linking the two.

The dining area is situated under the main gable, and a smaller roof outlines the window-seat area without enclosing it.

The project video illustrates the proposed design and how the house and garden relate.

Client feedback on extensions, conversions and renovations

Please read clients’ accounts of working with me on house extensions, a garage conversion and internal alterations. Their reviews describe the design discussions, communication and help with comparing options.

Front view of a Solihull house with a first-floor side extension above the garage, a replacement glazed porch and a brick and rendered exterior.

"We needed more space, but didn’t want to leave the area. We got the extra bedroom without moving, thanks to the first-floor extension designed by McTernan Design. We were able to see exactly how the spaces would work in 3D."
Sarah & James, Solihull, Householder planning (Side extension)

Proposed 3D view of a steel-framed barn conversion in the Cotswolds, with timber cladding, a glazed gable, first-floor balcony and adjoining single-storey wing.

"If you’re thinking of a renovation, or a new build, or any type of alteration to your property, I would highly recommend Mark to be appointed. He is very professional and very much on the ball, always. Always happy to go through the smallest information with as much as detail as possible, and step to step guide and opinions"
Noorul, Kings Heath, Birmingham, PD & Householder planning (Side & rear extensions)

Rear garden view of a Cotswold stone house with a contemporary flat-roofed glazed extension and adjoining timber-clad garage with partial conversion.

"Highly recommended. Mark assisted us with the design of a rear extension, garage conversion and redesign of several other interior rooms. Excellent, responsive service which helped us not just narrow down our options but helped us think about things we hadn’t ever even considered."
Tom, Stratford-Upon-Avon, Householder planning (Garage conversion, rear extension and internal renovation)

Planning application drawings and Building Regulations drawings

Proposed front view of a replacement family home in Stratford-upon-Avon, with brickwork, timber cladding, a glazed entrance gable and double garage.

Planning drawings communicate the proposed building and site changes for the relevant application. Where a planning application is required, I prepare and submit the drawings and supporting information after the design is agreed, and keep you informed about its progress.

Building Regulations drawings develop the agreed design into architectural construction details and specifications. I coordinate the structural engineer’s design information where needed. The technical information provides a basis for assessment, builder quotations and construction within the agreed scope.

Your written quotation sets out the stages, drawings, services and fees included, so you can see what you are commissioning before work begins.

View architectural design services or read how the design process works.

What to send when you first enquire

You do not need a completed design or a full brief to enquire.

Please send your property or site address and a few lines describing what you want to change or build. Photographs, rough sketches, and existing drawings are helpful but not required.

Include any questions about planning, neighbours or when to involve a builder.

My free desktop appraisal reviews the information you send, possible approaches and the relevant planning considerations. I will contact you to discuss the next step and explain how I can help before you decide whether to commission further work.