Designing a one-off house in Ireland: the brief, county design guides and stock plans

Months before anyone needs a builder, a one-off house is a design problem: you have, or are buying, a site, and you need a house that fits your budget and that the council will grant. The design is also the largest lever on cost. Get it right early and every later guide (planning, finance, build, insurance) gets easier.

To choose who designs it, see architect or engineer for a self-build. For the application, see planning permission for a one-off house.

Write a design brief first

A design brief is a short document you give a designer so they can draw something useful on the first attempt. One page is enough. It saves design fees because the designer is not guessing, and it stops you buying a plan for a house that your site or budget cannot take.

Cover these:

• Budget. The total you can spend on the build, with the contingency held back. Work this out with the self-build cost calculator and the cost to build guide. Say so plainly: a designer who knows the number designs to it.
• Rooms. How many bedrooms and bathrooms, and the spaces you need that are not rooms: a utility, a home office, a boot room, storage.
• How you live. Where you want morning sun, where the kitchen meets the garden, who needs to be near whom.
• Orientation. Which way the site faces, and what you want to see. The main living rooms facing roughly south gain the most from the sun. The Cork guide’s checklist asks whether the main living spaces are within 15 degrees of south.
• Future needs. A house that works for a growing family, a parent moving in, or reduced mobility. Ground-floor bedroom and bathroom space and wider doors cost little at design stage and a lot to add later.
• Constraints. Wastewater system and where it goes (see site suitability assessment), access, services, trees, the local-need condition, and any size limit the council has told you about.
• Energy. Part L compliance is required; ask whether you want to go beyond it. See Part L and nZEB.

Keep the first draft short. List what must be there, what you would like if the budget allows, and what you do not want. Be ready to cut: a brief that asks for everything will cost more than you have.

Read your county’s rural design guide

Many county councils publish guidance on siting and designing a house in the countryside. It is usually a PDF with photographs and sketches, and it is often attached to or referred to by the county development plan. Each council’s planning pages may carry a newer edition than the links below, so confirm the current version before you rely on it.

County	Guide
Cork	Cork Rural Design Guide
Clare	Clare Rural House Design Guide
Kildare	Rural House Design Guide, Appendix 4 of the 2023 to 2029 plan
Meath	Rural Design Guide
Kilkenny	County Kilkenny Rural Design Guide
Roscommon	Rural design guidelines
Laois	Rural design guidelines
Galway	County Development Plan 2022 to 2028, chapter 4 (rural design policy; the older stand-alone Galway guide link no longer works)

If your county is not here, search the council’s planning pages for “rural design guide” and check the county development plan’s rural housing chapter. Ask the planning office whether there is one. Reading the guide for your county is more useful than reading all eight, because they differ in detail, but they agree on the main ideas:

• Fit the site. Use the shelter of a hedge, trees or a fall in the land, and keep off the skyline. The Kildare guide lists prominent hillside sites and ridges, road-frontage sites and building in front of the established building line among things to avoid.
• Keep the form simple. Kildare advises against deep floor plans and a profusion of shapes, roof pitches, projecting gables and bays. It suggests narrow plan elements joined together, such as a single storey linked to a two-storey part.
• Roof pitch. Kildare says indigenous rural houses tend to have side gables and slopes of 35 to 45 degrees; Clare gives 35 to 55 degrees. Both prefer few ridge lines and valleys. The Clare guide lists low-pitched roofs and disproportionate windows among its examples of poor design.
• Proportion of walls and openings. Windows with a vertical emphasis sit more comfortably than wide, horizontal ones, but the guides stop short of rules.
• Materials and colours. Plain finishes in colours found locally. Check what each guide says about render, stone, slate and cladding.

None of this is a rule you can be refused for breaking in itself. The guides are advice, and the planning decision rests on the county development plan and the planner’s view of the site. But if your design departs from the guide, be ready to explain why in your planning drawings or a short design statement.

Design reasons for refusal

Councils refuse one-off houses for policy reasons (the applicant does not meet the local-need condition) and for design reasons. Policy refusals cannot be fixed by redrawing the house. Design refusals can. The common design reasons, and what usually answers them:

Reason	What the planner means	What to change
Siting	The house sits on a ridge, in the middle of an open field, or too close to the road.	Move it back, down, or against existing trees and hedges. Use the part of the site with a natural backdrop.
Scale	The house is too big for the site or the landscape.	Reduce the footprint. Break it into linked, narrower parts. Consider a storey and a half.
Height	A tall ridge or high floor level stands out.	Lower the ridge, reduce the floor-to-floor height, or sink the house into the slope.
Glazing	Large areas of glass, especially facing the road or a view, read as an inappropriate modern intrusion.	Reduce and reposition the glazing, put the large openings on the private side, and set out the windows in a pattern with the wall.
Finishes	Colours, cladding or materials that contrast with the area.	Choose plain, local-looking finishes and say what they are on the drawings.

Before lodging, ask the planning office for a pre-planning meeting and bring the drawings. See planning permission for a one-off house for how that works. If you have already been refused, read one-off house planning refused for how to read the decision notice and choose between an appeal and a fresh application.

Stock plans or a bespoke design

Stock or catalogue plan

• Cost. The plan’s price, plus the cost of adapting it to your site. Get both in writing.
• Fit to your site. Drawn for no site, so it needs adapting to levels, orientation and access.
• Planning fit. Only as good as the adaptation. Check it against your county’s guide.
• Cost certainty. Often comes with a known form or a bill of quantities. Ask.
• Certification. You still need someone to take responsibility for the design under the Building Regulations.

Bespoke design

• Cost. A designer’s fee, commonly a fixed amount per stage or a percentage of build cost. See the architect guide.
• Fit to your site. Drawn for your plot, brief and budget.
• Planning fit. Can be designed to the guide and discussed with the planner.
• Cost certainty. Depends on the brief and on how early the design is checked against the budget.
• Certification. Your designer can usually do this as part of the service.

This guide gives no price for stock plans because there is no reliable published figure; ask each supplier. A stock plan is not a shortcut around a designer. It saves time on the first drawings, but someone still has to adapt it to the site, check it against the Building Regulations in force, and prepare the planning drawings.

If you are on the statutory certification route, you need a design certifier and an assigned certifier, and each has to be an eligible registered professional. A supplier of plans may not be one. Before you buy, ask in writing who will certify the design, what it will cost, and whether they have seen the plan. See assigned certifier explained and commencement notice and BCAR.

Design and cost

Most of the cost of a house is decided on the drawing board. What drives it, in rough order:

• Total floor area. Cost scales with it more than with anything else. A smaller house that is well planned often feels as large as a bigger one with wasted corridors.
• Simple form. A rectangle with a single pitched roof costs less than a house with several wings, valleys and projecting bays. This matches what the county guides ask for, so it helps twice.
• Compact versus spread. A house with more outside wall for its floor area costs more to build and to heat. A bungalow has more foundation and roof than a two-storey house of the same floor area. Kildare’s suggestion of a single storey linked to a two-storey part is a compromise between form and cost.
• Spans and structure. Long unsupported spans, large openings and complicated roof shapes need steel or engineered timber. Ask the designer which parts of the design drive the structure.
• Glazing. Large window areas cost more in glass, frames and thermal performance. See windows and doors for a self-build.
• Level and access. A sloping site can add excavation, retaining and drainage costs. A designer may fit the house into the slope instead.

Ask your designer to price at least two options early, such as a compact two-storey form and a storey-and-a-half form, before you commit to detailed drawings. Put the result into the self-build cost calculator and the stage payment planner.

Design choices that change your insurance

Your insurance depends on what is being built and what sits on site. Two design choices matter:

• Timber frame. Who owns and insures the frame at each step (factory, delivery, erection) is worth settling before you commit to the design. See insuring a timber frame or modular build and timber frame vs block vs ICF.
• Large glazing units. Big glazed doors and windows are expensive and fragile, and may be delivered before they can be fitted. See the stored-units section of windows and doors for a self-build.

For the cover that matches your stage, use What insurance do I need? and read self-build insurance. If the plot is already yours, insuring your site before you build covers what applies now.

Before you sign a design contract

• You have written a one-page brief with a budget and what must be there.
• You have read your county’s rural design guide, or asked the planning office whether one exists.
• Your designer has said how the design will meet the guide and the local-need condition, and how they will price it.
• You know who will be your design certifier and assigned certifier, and what each will cost.
• You have asked for two forms to be priced, not one.
• If you are buying a stock plan, you have written confirmation of who adapts it, who certifies it, and what that costs.