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3D Home Architect and low cost CAD programs

What you can (and can’t) do with a low cost CAD program, plus an example studio house and the drawing lessons we kept from our old tutorial.

3D Home Architect version 3 is not sold any more. John wrote these notes while it was, and the tutorial was written for CountryPlans by Bob Heaney, a member of the forum. The five lessons further down are still here because people still land on them from a search, and what they show about roofs, stairs and dormers does not depend on the program.

Low cost CAD programs are great for floorplan layouts and getting a feel for the space you will be building. They will not have the structural information to let you design a full set of construction drawings.

These programs can do real work if you have a stock plan that has the structural information and you want to change the windows, doors and non-structural walls inside that structural shell. In some cases you can even change the outside dimensions without altering things too much.

With any modified design a local home designer, architect or engineer should review the drawings to make sure it meets local codes and is structurally sound. If you’ve made changes that require additional drawings or details, then this person can provide them for you. Often this person can make suggestions about local materials or building techniques that will work better or save you money over what is called out in the stock plan. There are considerable regional differences in how houses are built.

The older 3DHA ver. 3 program does the basics in a straightforward easy to learn way. It lets you quickly layout walls to form a building shape. Then you drop in doors, windows, furniture, and cabinets. Click a few more buttons and you put a simple roof over it. To see the space you’ve just designed, simply grab the eyeball icon and drag it in the direction you want to look. Let go and the program draws an interior (or exterior if you’re outside the walls) perspective. The program will frustrate those who want to design an elaborate house with a complex roof. It is best used to design simple buildings. For buildings like this it can give you a full 3D model.

For a more complex building you can use a home design program as a floorplanning tool to get a feel for the interior and how much space you need for furniture, cabinets, appliances, etc.

An example studio house

Below is a couple of screen shots of a studio house done in 3D Home Architect. The plan can be printed out to scale and used directly in the final drawings. This small house has an open bedroom loft over a small kitchen/bath area. The tall walls give the place an old school house feel.

Floor plan of the studio house, 35 feet by 18 feet. A kitchen and bath fill one end with stairs going up beside the bath, and the rest is one living space with a woodstove or fireplace on the far wall.
Example floor plan. We could add electrical fixtures and additional notes and dimensions if needed.
Interior perspective of the studio house drawn from the fireplace end, looking past tall windows to the kitchen, with a railed sleeping loft open above it and stairs running up beside the kitchen wall.
This is an interior perspective taken from the fireplace.

The drawing lessons we kept

These five were written for 3D Home Architect version 3. The drawings still hold up. The steps that name buttons inside the program are the part that has aged.

Cross section of a traditional salt box home. The long roof runs from the ridge down past the second floor to a low eave, a 12-in-12 pitch is noted at the ridge, and a formula at the top left gives the minimum width of the lean-to side.

How a salt box roof works

Drawings of the salt box roof in cross section, with the pitch table and the minimum width of the lean-to side.

Drawing of a stairway turning at a landing, with arrows labelling the landing, the treads, the risers, the riser height, the rise angle, the best tread and the sections.

Stairs and how they work

The parts of a stairway drawn and named: treads, risers, riser height, landings, sections and rise angle.

Cross section of a roof at a 26.57 degree slope, with a 6 inch rise marked on the vertical and a 12 inch run marked along the horizontal.

Slope, hip and gable

What roof pitch means, drawn in cross section, and what a hip roof section looks like next to a gable.

Two gabled dormers set into the front slope of a roof, shown from outside above and in cross section below, with the dormer roof meeting the main roof circled.

Adding dormers

Dormers drawn into an attic space, with the knee walls and the ceiling heights shown.

Where to go from here

Free articles on land, foundations, framing and permits are on the Resources page.

If you want to ask someone who has drawn one of these before, the discussion forum is free to read and free to join.