Permit-Ready Tiny House Plans and Engineering
Tiny house plans on permanent foundations, drawn to the tiny house provisions your jurisdiction has adopted and sealed for permit.
- Stamped by a PE licensed in your state
- Built to IBC, IRC and local amendments
- Plan-check comments answered
Tiny house plans built for the permit counter
A tiny house can be the simplest home you ever build or the hardest one to permit. Plans from the internet rarely address local snow, wind and seismic loads, the energy code, or the specific rules for lofts, ladders and ceiling heights that apply to very small dwellings. PE Engineer prepares tiny house plans that close those gaps, so the building department sees a complete, code-compliant set instead of a sketch.
Our work covers tiny houses built on permanent foundations as primary homes, backyard cottages and accessory dwelling units. Where your jurisdiction has adopted IRC Appendix AQ, the tiny house appendix of the International Residential Code, we use its provisions for homes of 400 square feet or less, excluding lofts. Where it has not, we design to the standard IRC requirements, which a well-planned small house can still meet. Every set is sealed by a Professional Engineer licensed in the state where the house will be built.
We can start from your own layout, from a purchased stock plan, or from a builder’s design that needs engineering and code review. You receive a fixed-fee proposal first, usually the same day, and most residential packages are delivered within a few business days of receiving complete information.
What you receive
- Floor plan, loft plan and elevations
- Building sections with ceiling heights
- Foundation plan and details
- Framing plans and connection details
- Structural calculations and code notes
- PE stamped PDF set ready to submit
What our tiny house plans include
A tiny house still needs everything a full-size house needs, just organized for a much smaller footprint.
Architectural plans
Floor plan, loft plan, exterior elevations, sections and a door and window schedule, drawn so the reviewer can verify ceiling heights, egress and loft access.
Loft and access design
Sleeping and storage lofts with guards, plus stairs, ladders, alternating tread devices or ship's ladders as permitted by the tiny house provisions your jurisdiction has adopted.
Foundation design
Slab, stem wall, crawlspace or pier foundations sized for your soil and frost depth, with anchorage that resists wind uplift and overturning on a light building.
Framing and lateral design
Roof, floor and wall framing sized for local snow and wind, with braced wall or shear wall design that works with a small footprint and many windows.
Code compliance notes
Energy code, smoke and carbon monoxide alarm, ventilation and emergency escape opening notes, so the plan reviewer can check each item without guessing.
Engineering for prebuilt units
Foundation and tie-down design for a tiny house built off site and set on a permanent foundation, where the jurisdiction treats it as a dwelling.
Your Stamped, Permit-Ready Plans Start With One Upload
Send your drawings or describe the project. A licensed engineer reviews it and sends a clear, fixed-fee proposal, often within hours.
- Free and no obligation
- Reviewed by a licensed PE
- Secure file upload
Tiny house plans and IRC Appendix AQ
The International Residential Code includes an appendix written specifically for tiny houses. It is labeled Appendix AQ in recent editions and appeared as Appendix Q in earlier ones. Because it is an appendix, it applies only where a state or local jurisdiction has chosen to adopt it, and some adopt it with amendments.
Where it is adopted, the appendix relaxes several requirements that are difficult to meet in a very small home, while keeping the safety basics. It addresses:
- Minimum ceiling heights in habitable spaces, bathrooms and kitchens, with reduced heights allowed in some areas.
- Lofts used for sleeping or storage, including minimum size, height and guard requirements.
- Loft access by stairways with reduced dimensions, ladders, alternating tread devices or ship’s ladders.
- Emergency escape and rescue openings, including roof access windows serving lofts.
We read your jurisdiction’s adoption carefully, including any local changes, and draw the plans to match. Where the appendix is not adopted, we design the house to the standard IRC provisions for stairs, ceiling heights and egress, and we show you early where that affects the layout, such as a loft that needs a real stair instead of a ladder. Either way, the tiny house plans clearly cite the provisions used, so the reviewer can follow the code path without having to ask.
Foundations and the difference between tiny houses and THOWs
How a tiny house sits on the ground determines how it is regulated. A tiny house built on a permanent foundation is a dwelling under the building code, reviewed like any other house. A tiny house on wheels, often called a THOW, is usually treated as a recreational vehicle or park model RV, built to a separate RV standard and certified through a separate program. Local zoning then decides where and how long it can be occupied.
PE Engineer designs tiny houses for permanent foundations. We do not provide RV certification or design homes to RV standards. Where a jurisdiction allows a tiny house built off site to be removed from its trailer and placed on a permanent foundation as a dwelling, we can design that foundation and the anchorage, and coordinate with whatever structural documentation the jurisdiction requires for the house itself.
For site-built and permanently placed tiny houses, common foundation choices include:
- A monolithic slab with thickened edges, simple and economical on level lots.
- A short stem wall over a crawlspace, which keeps the floor dry and plumbing accessible.
- Concrete piers or helical piles, useful on slopes and where disturbance should be limited.
Because tiny houses are light, wind uplift and overturning often govern the anchorage more than gravity loads do. For factory-built homes placed on a site, see our manufactured and modular home foundations service.
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- Free and no obligation
- Reviewed by a licensed PE
- Secure file upload
Structural design for a small footprint
Small homes have structural quirks. Large windows and a loft opening leave little solid wall for bracing. A steep roof chosen for headroom in the loft adds height and wind exposure. Snow loads in mountain regions can be heavy relative to the framing a short-span roof might otherwise use. A loft floor spanning the full width with a ladder opening needs a clear load path to the walls below.
We address each of these with a structural design sized to the actual loads:
- Roof framing sized for local ground snow, drifting at roof steps, and wind uplift at the eaves.
- Loft floor framing designed for its intended use, with guards detailed to resist the required loads.
- Braced wall panels or engineered shear walls placed where the plan allows, with hold-downs where needed.
- Connections from roof to wall to foundation that complete the uplift load path.
Wood framing is designed to the NDS and the IRC, with loads from ASCE 7 for your location. The result is a tiny house that is efficient to build and straightforward for the inspector to verify.
Tiny houses as ADUs and what we need to start
Many tiny houses are built as backyard units behind an existing home. In that case the project is usually reviewed as an accessory dwelling unit, which brings zoning rules for setbacks, height, parking and utility connections in addition to building code review. Our ADU plans service covers the planning side, and a site plan showing the new unit, setbacks and utilities is often required with the submittal.
To prepare a fixed-fee proposal, send us:
- The site address, so we can confirm the adopted code, whether the tiny house appendix applies, and local design loads.
- Your layout sketch, a stock plan or a builder’s drawings.
- Whether the house will be built on site or built elsewhere and set on a foundation.
- The intended use, such as primary home, ADU or guest cottage.
- Any comments or requirement lists from the planning or building department.
If the reviewer has comments after submittal, we answer each one and revise the drawings within the original scope at no extra charge.
Utility connections also need attention. A tiny house on its own lot needs its own water, sewer or septic and electrical service, while a backyard unit usually connects to the main house. We note those connections on the plans so the reviewer sees the complete picture.
You likely need this if
- You are building a tiny house on a foundation
- Your city adopted the IRC tiny house appendix
- Your stock plan lacks local engineering
- You are adding a tiny ADU in your backyard
- A prebuilt tiny house needs a foundation
- The reviewer asked about lofts or egress
How it works, start to finish
From your first message to stamped drawings, you work directly with the engineering team.
- 1Share your projectSend the address, scope and any drawings, photos or plan-check comments. Two minutes is enough.
- 2Receive a fixed-fee proposalAn engineer reviews the scope and replies with a firm price and delivery date for your tiny house plans drawings.
- 3Engineering and draftingWe run the calculations and prepare drawings to the codes your jurisdiction enforces, checked before sealing.
- 4Stamped set deliveredYou receive a sealed PDF set ready to submit, and we answer any plan-check comments within scope.
Codes and standards we design to
Tiny house plans follow the editions your jurisdiction has adopted, including local amendments and zoning rules:
- International Residential Code (IRC)
- IRC Appendix AQ, Tiny Houses, where adopted
- ASCE 7 for snow, wind and seismic loads
- NDS for wood framing and connections
- ACI 318 for concrete foundations where engineered
- International Energy Conservation Code (IECC) or your state energy code
How licensing works. Engineering drawings must be sealed by a Professional Engineer licensed in the state where your project is located. PE Engineer works with a network of state-licensed PEs, so every set is reviewed and stamped by an engineer with an active license in the state where your project is located. Their name and license number appear on the seal, exactly as your building department requires.
Related services
ADU PlansPermit-ready ADU plans for detached units, garage conversions, additions and basement units, with site, architectural, structural and energy sheets in one set.Explore More
Foundation DesignFootings, slabs, stem walls, piers and pile foundations designed and PE stamped for your soil, loads and local code.Explore More
Manufactured & Modular Home FoundationsPermanent foundation design and certification letters for manufactured homes, plus pier, anchor and modular home foundations, plot plans and grading, PE stamped.Explore MoreFrequently asked questions
What is IRC Appendix AQ?
It is the tiny house appendix of the International Residential Code, covering dwellings of 400 square feet or less, excluding lofts. It provides alternatives for ceiling heights, lofts, loft access and emergency escape that suit very small homes. It applies only where your state or local jurisdiction has adopted it, sometimes with amendments.
Can you design a tiny house on wheels?
We design tiny houses on permanent foundations. A tiny house on wheels is usually regulated as a recreational vehicle or park model RV and certified under a separate program, which we do not provide. If your jurisdiction allows a tiny house to be set on a permanent foundation as a dwelling, we can design that foundation and anchorage.
Can I use a stock tiny house plan for my permit?
Often, yes, with engineering added. Stock plans are rarely designed for your local snow, wind, seismic and soil conditions or your adopted code. We review the plan, design the foundation, framing and connections for your site, add code notes, and seal the set for your jurisdiction. The finished set carries your local design loads and the seal of an engineer licensed in your state.
Can a sleeping loft use a ladder?
Where IRC Appendix AQ is adopted, loft access by ladders, alternating tread devices and ship’s ladders is permitted within the limits the appendix sets. Where it is not adopted, a loft used as habitable space generally needs a stairway meeting the standard IRC requirements. We confirm which applies before the layout is finalized.
Is a tiny house cheaper to permit than a regular house?
The drawings are smaller, so the engineering fee is usually lower, but the permit still covers the same disciplines: structure, energy, egress, plumbing, electrical and zoning. We send a fixed-fee proposal for the plans after reviewing your project, usually the same day. Small homes still benefit from careful planning to avoid costly redesign.
Do you provide plans for a tiny house ADU?
Yes. Tiny houses are a popular backyard ADU option. We prepare the architectural and structural plans for the unit, and can include a site plan showing setbacks and utilities so the planning and building reviews have what they need. Zoning setbacks and height limits for ADUs vary by city.
Get your free tiny house plans proposal
Tell us where the project is and what you need. Attach any drawings, photos or plan-check comments. A licensed engineer reviews every request.
- Upload your filesPlans, sketches, photos or comments
- Get a fixed-fee proposalUsually the same day
- Receive stamped drawingsSealed by a PE licensed in your state