How do construction drawings differ from DA drawings?

What do DA drawings show?

DA drawings are prepared for a development application (DA), so they answer the questions a council planner asks about the home and its neighbours. The City of Sydney's document requirements give a clear picture of a typical set. It starts with a site plan showing boundaries, existing buildings, trees and levels, all based on a survey of the land.

Floor plans then show the room layout, setbacks from the boundaries and the total floor area. Elevations from every side and at least one section show the roof profile, external materials and colours, along with existing and finished ground levels. Planners use these drawings to test height, bulk, privacy, overshadowing and how the house sits in the street.

A DA set generally carries less construction detail than the set that follows, because council is deciding whether the home suits the site. How a wall is waterproofed or how a beam is sized usually comes later. Council may still ask for some technical material with the DA, such as a stormwater drainage design for a new building or a geotechnical report where excavation is proposed. What the DA set holds depends on the site and the proposal.

What do construction drawings add?

Construction drawings, often called working drawings or the construction certificate set, carry the detail a builder needs to price and build the home. The NSW Government's guide to the post consent process says these plans usually include more detail than the approved DA plans, so the builder can work directly from them.

The guide lists architectural plans, elevations, sections and details alongside building and construction specifications covering materials, finishes, waterproofing and energy. Structural engineering plans for the slab and framing come next, with stormwater plans and a geotechnical assessment where the site needs them. The BASIX certificate sits in the set as well. The City of Sydney notes that some BASIX commitments must appear on the DA plans and others only on the construction plans.

Because a construction certificate can only carry conditions where legislation provides for them, the post consent guide warns that this set has to be fully detailed. It also says preparing the set can take several months, so allow for that time between consent and the start of work.

Why must the two sets stay consistent?

The construction drawings have to describe the same home council approved. A construction certificate confirms that the detailed plans are consistent with the development consent and comply with the Building Code of Australia, as Service NSW puts it.

Detail is expected to grow between the two sets, while the approved design is not meant to change. The Department's DA guide says any plan change that is inconsistent with the DA plans must be assessed to see whether you need to modify the consent. A taller roof, a moved window or a larger footprint can all send the project back to council.

Conditions of consent can change the drawings too. A condition might reduce the height or add a privacy screen, so the construction set must show the approved version rather than the one you lodged.

How we keep DA and construction drawings aligned

At SHORE Design + Build our architect and our builders work in the same studio. We resolve the design inside and out during design development, before the DA is lodged, so the construction drawings refine the approved home rather than reinvent it. Our working drawings, specifications and schedules are then prepared by the people who will build from them. The drawings that win approval are the drawings we build from.

If another architect has already designed your home, our guide to finding a builder for your architect's plans covers what to send a builder with each set. You can also see each stage in how we design and build a home or explore design and build in Sydney with us.