As-built plans: what they are, an example, and when you need one

Someone has asked you for the as-built plans. It might be the building office, because you want to add a room, or a buyer’s bank, or the engineer looking at a second floor. And the house you are standing in was built years ago, from drawings nobody can find, and has been changed twice since.

That gap between the house on paper and the house on the ground is what an as-built plan closes.

What an as-built plan is

An as-built plan is a set of drawings of a building as it actually stands, measured on site. Design drawings show what was meant to be built; as-built drawings show what was built, including every change made during construction and every one made after it.

The same set is often called as-built drawings, and the two names mean the same thing. It is written “as-built”, with a hyphen. You will also see it spelled “as build”, on forms as well as in searches, and it means the same request.

An as-built set comes about in one of two ways:

• Marked up during construction. The contractor marks every change on a copy of the permit drawings as the work goes, often in red, and the architect redraws the set from those mark-ups when the house is finished. This is the cheap way, and it only works if someone does it at the time.
• Measured afterwards. For a house that is already standing, and especially an older one, someone has to measure it from scratch. Most as-built work on existing Philippine houses is this kind.

An example as-built floor plan

This is what a sheet from an as-built set looks like, and the conventions it uses. Each change from the original drawings carries a numbered revision triangle, explained in the notes. Work that has been removed is drawn dashed, so nobody mistakes it for something still standing. The title block is stamped AS-BUILT, and on a real sheet it also carries the date the house was measured.

1. 1The window was moved during construction. The dashed outline is where the permit drawings put it; the solid window is where it is.
2. 2The carport was enclosed and has been used as a second bedroom since. It is drawn as it is used today.
3. 3A wall taken out in a later renovation, drawn dashed so nobody assumes it still carries anything.

As-built drawings compared with other drawings

Drawing	What it shows	Who makes it, and when
Design or permit drawings	What is meant to be built	The architect and engineers, before construction, signed for the building permit
Shop drawings	How one part is to be made or installed, such as the steel trusses, the windows or the cabinets	The contractor or the fabricator, during construction, for the architect to check
As-built drawings	What was actually built, including every change	Marked up during construction, or measured afterwards
Record drawings	The final set kept on file for the building	Usually the designer, updating the design drawings with the contractor’s mark-ups

A floor plan is one sheet of a set. An as-built set includes floor plans, along with the other sheets listed further down this page.

Why the house rarely matches the old plans

Almost no house is built exactly to its permit drawings. A window moves because the contractor found a column in the way, a stair turns the other direction, a room gains a metre because the owner asked for it on a Saturday. Then the years add their own changes: the carport becomes a bedroom, the dirty kitchen moves outside, a sari-sari store opens in the front room.

None of that is on the original set.

So a renovation drawn over the old drawings is drawn over a house that no longer exists, and the mistakes surface on site, at the point where fixing them costs the most.

When you need one

• Renovating or extending. New work has to meet the walls, beams and pipes that are really there.
• Adding a second floor. Before anyone can say whether the house will carry another storey, they need to know what is holding up the first one.
• A permit for work on an existing house. The building office reviews new work against the building it joins, so the application needs drawings of that building.
• Changes made while it was being built. Approved plans may not be changed without the Building Official’s approval (PD 1096 Section 304). A house built differently from its permit drawings needs those differences drawn and put through the office before the occupancy permit.
• Selling, buying or borrowing. A buyer, a bank or an insurer can ask for drawings that match the property, and the ones in the drawer often do not.
• Paperwork that was never finished. An older house that was lived in without an occupancy certificate sometimes has to be documented before that can be put right. The occupancy permit guide explains what the certificate needs.

Who prepares and signs it

An as-built plan is measured and drawn by an architect or an engineer. For anything going to the building office, each sheet has to be signed and sealed by the professional whose licence covers it: the architectural sheets by an architect, the structural by a civil engineer, the electrical by an electrical engineer, and the plumbing and sanitary sheets by the professionals licensed for them.

A set drawn by someone without a licence can still help you plan. It cannot go to the building office.

As-built plans by trade

Each discipline has its own as-built sheets, drawn and signed by the professional whose licence covers it, as the guide to reading a house plan sets out.

• Architectural. Walls, doors, windows, stairs, room sizes, levels and finishes, as they stand. This is what most people mean by an as-built plan.
• Structural. The columns, beams, slabs and roof frame that can be seen, with their sizes. What is hidden, such as the footings and the reinforcement, is marked as assumed unless it is opened up or the original structural drawings survive.
• Electrical. The panelboard and its breakers, the circuits, and where every outlet, switch and light actually is. An as-built electrical plan matters most before an aircon unit, a second floor or a solar system is added, because each one puts new load on circuits nobody has traced.
• Plumbing and sanitary. The water line, the drains and their cleanouts, the floor drains, and where the septic tank really sits. The septic tank guide covers the distances the tank has to keep.

How one is made

1. A site visit. Every room is measured, usually with a tape and a laser distance meter: walls, doors and windows, ceiling heights, floor levels, and the thickness of each wall, which says a good deal about what it is made of. Large buildings are sometimes captured with a 3D laser scanner; for a house, a careful measured survey is the usual method.
2. The structure and services, wherever they can be seen. Columns, beams, the roof frame from the ceiling space, the electrical panel, the water line and the septic tank.
3. Photographs, so every dimension can be checked later against what was actually there.
4. Drafting, usually in CAD, into plans, elevations and sections at a proper scale.
5. A return to site for anything that did not close. A room whose sides do not add up is a measurement missed, and this is the cheapest moment to catch it.

Nobody can measure inside a wall or under a slab without opening it. A careful set marks what was seen and what was assumed, so nobody later sizes a beam on the strength of a guess.

What a set usually includes

• A site plan showing the house on the lot, with the setbacks as they really are
• Floor plans of every level
• An elevation of each side
• At least one section through the house
• A roof plan
• Electrical and plumbing layouts, where the work ahead needs them

The site plan is often the sheet that surprises people. It is where an old extension turns out to sit closer to the boundary than the rules for that lot allow, which is far better learned before a permit application than during one.

What it does not tell you

An as-built plan records what is there without saying whether it is sound. Cracks, sagging, damp and rusted reinforcement are a separate question, answered by an assessment of the structure. If you plan to build on top of what is there, have both done at the same visit.

Where this practice fits

Arktektura measures and draws as-built plans and assesses the structure in the same visit, across Pampanga, Bulacan, Tarlac, Bataan and Olongapo. The as-built plans and site assessments service covers that work. If the drawings are for a permit, the building permit guide explains what else the office will ask for, and renovate or rebuild helps once you know what you are working with.

This guide describes common practice. Requirements differ between municipalities, so confirm what your building office needs before the drawings are made.