How to plan a small HO layout
A well-planned small layout beats a half-built big one. Measure your space, choose your curves, and draw it at full size before you buy track.
- Time
- 2–3 hours
- Difficulty
- Easy
- Cost
- Low cost
- Steps
- 8
- Checked
What you’ll need
- Tape measure Search Amazon for tape measure 5m
- Squared paper or track planning software
- Pencil and rubber
- Roll of lining paper for a full-size template Search Amazon for lining paper roll
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Take care
- Make sure the baseboard is stable and can't tip if someone leans on it.
Step by step
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Step 1: Measure the space honestly
Measure length, depth and height, and note doors, radiators and sockets. Allow room to reach every part of the layout: most people can reach about an arm's length comfortably, so deep boards need access from both sides or an access hatch.
Next: step 2 -
Step 2: Choose your type of layout
- Oval or continuous run — trains go round; needs depth for curves.
- Shelf or end-to-end — trains shunt between sidings; fits long, narrow spaces and needs no curves.
- Around-the-room — long run on narrow shelves; needs corner curves.
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Step 3: Work out the curve space
Your smallest curve sets the board depth for an oval. Twice the radius plus clearance at each side: for example 2 × 360 mm = 720 mm across the track centres, so plan at least 80 cm plus a safety margin. Larger curves look and run better — see choosing a minimum radius.
Next: step 4 -
Step 4: Use the track system's geometry
Set-track systems are designed on a grid: Piko A-track uses a 470 × 61.88 mm unit, Roco geoLine 385 × 76.5 mm, and Märklin C-track is laid out on its own grid. Use the maker's track plans or planning software so the pieces actually fit.
Next: step 5 -
Step 5: Draw it at full size
Sketch on squared paper first, then draw the key parts — curves and points — full size on lining paper laid on the board. You'll spot tight spots and missing clearances before buying track.
Next: step 6 -
Step 6: Plan the operation
Think about what the trains will do: a passing loop, a goods yard, a station. A run-round loop must be longer than your longest loco plus a train.
Next: step 7 -
Step 7: Plan wiring and access early
Mark where feeds and point motors will go and how you'll reach them. Plan the controller position at the front.
Next: step 8 -
Step 8: Plan gradients and clearances
If you want a line to climb over another, check you have enough length — at a 2% gradient a 4 in (about 10 cm) rise takes about 16 ft (4.9 m). See building a gentle gradient.
Tips
- Start small and finish it — you'll learn more from a completed small layout.
- Keep points away from the edge of baseboard joints.
Questions people ask
What size board do I need for a simple oval?
Around 1.2 m × 0.8 m works for an oval of about 360 mm radius curves; larger curves need more.
Can I build a layout with no curves?
Yes — a shelf shunting layout needs no curves at all and fits small spaces.
Sources
Checked 18 October 2026. We wrote this guide in our own words, using:
- PIKO A-track brochure (piko-shop.de)
- Roco geoLine instructions (German, via Conrad) (asset.conrad.com)
- Märklin: curved C-track R1 = 360 mm (24130) (maerklin.de)
- NMRA RP-11: curvature and rolling stock (2018) (nmra.com)
- Woodland Scenics: 2% incline/decline set (ST1410) (woodlandscenics.woodlandscenics.com)
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Printed from locoho.co.uk/guides/how-to-plan-a-small-ho-layout/ · Checked 18 October 2026 · General information only. Always follow the manufacturer’s instructions for your trains, track, controllers and decoders.