Quick answer: A building plan is the set of drawings that shows how a building is laid out and how it will be built: the site plan, floor plans, structural plan, services plan and landscape plan. An architect and engineers prepare it, the local authority approves it, and the contractor builds from it. Construction should not start before the plan is sanctioned.
No house, office or apartment block gets built well without a plan. The plan fixes what is to be built before money is spent on site, and every later decision, from the foundation to the switchboards, is taken from it. This guide explains what a building plan is, the drawings it contains, the stages of planning, who prepares it and what to check before you approve yours.
What is a building plan?
A building plan is the set of documents that shows how a construction project is designed: where it sits on the plot, its architecture, its technical details and the materials to be used. It works as the blueprint for the project. The authority uses it to check the building against the rules, the contractor uses it to build, and the owner uses it to know what is being paid for.
Types of building plans
- Site plan: shows the plot boundary and its dimensions, the position of the building on the plot, nearby features, and utilities such as water lines, drainage and electric supply.
- Floor plan: shows each floor from above: the rooms, their sizes, the positions of doors and windows, and how the space is divided.
- Structural plan: shows the footings and foundation, column and beam sizes, slabs, stairs and lift details, and the loads the structure is designed to carry.
- Services plan: shows the electrical and plumbing layouts, so the services work safely and do not clash with the structure.
- Landscape plan: shows the open areas: lawns, planting beds, pathways, courtyards and verandahs.
Each of these is prepared by a professional, such as an architect, a civil engineer or a technician, and every one of them is needed during construction.
Sanction drawings and working drawings
Owners often assume that the approved plan is all the contractor needs. It is not. There are two sets:
- Sanction drawings are submitted to the authority. They show that the building follows the rules for the plot, and they carry little construction detail.
- Working drawings are issued for construction. They carry full dimensions, structural details, electrical and plumbing layouts, and door, window and finish schedules.
A contractor working only from the sanction drawing has to guess the rest on site, and that is where errors and extra costs come from.
Stages of building planning
- Site analysis: the plot, its surroundings, the climate and the soil are studied first.
- Concept development: basic layouts and forms are worked out from the site analysis and the owner’s requirements.
- Design: the layout is finalised, the structural drawings are prepared and the materials are selected.
- Budgeting and cost estimation: the total cost of materials, labour and services is worked out.
- Scheduling: the work is arranged in sequence and a completion date is set.
- Approval of the building plan: the plan is submitted to the local authority and approved under the zoning and building rules.
How is a building plan made?
Drawings can be prepared by hand, with scales and measuring tapes, or on a computer. Software such as AutoCAD, Revit and SketchUp is faster and more accurate, and comes with templates and built-in units.
Software helps, but it does not replace training. The plan has to satisfy the building rules, suit the structure and work for the people who will live in it. It is advisable to engage a professional architect for the design and a structural engineer for the structure.
What to check before you approve a floor plan
- Furniture fits: ask for the plan with beds, wardrobes, sofas and the dining table drawn to scale.
- Door and window positions: check door swings, and that windows give light and cross ventilation to every room.
- Staircase: its position decides the layout of every floor, so settle it early.
- Toilets and kitchen: wet areas stacked one above the other on each floor keep plumbing simple.
- Columns: make sure no column lands in the middle of a room or the parking space.
- Orientation: check the north point, where the sun falls, and any Vastu requirements.
- Rules: confirm that setbacks, height and covered area follow what your authority allows.
- Future needs: if another floor may be added later, the structure must be designed for it now.
How is a building plan approved?
The drawings are submitted to the development authority or municipal body for the area, together with the ownership documents and the fee. The authority checks the plan against its rules on land use, setbacks, height and covered area, and issues a sanction. The exact rules, documents and fees differ from one authority to another, so confirm them for your plot. Many authorities now accept applications online; see how to check building plan approval status online.
Advantages of a proper building plan
- Clear vision: everyone works towards the same building.
- Efficiency: work proceeds in sequence, with fewer stoppages and less rework.
- Cost control: quantities and costs are known before work starts. Without a plan, the cost usually ends higher than expected.
- Safety: a detailed plan removes many hazards on site and in the finished building.
- Compliance: building against local rules is illegal, and the rules exist to protect the people who use the building.
- Property value: a well-planned building is more comfortable to use and easier to sell.
Common mistakes
- Starting construction before the plan is sanctioned.
- Building from the sanction drawing alone, with no structural or services drawings.
- Changing rooms and openings on site without revising the drawings.
- Fixing the budget after the design instead of alongside it.
- Leaving electrical and plumbing layouts to be decided by the trades on site.
Related guides
To see what goes into the structural set, read structural (GFC) drawings explained. Our step-by-step guide on how to design a house like an architect covers the design stage, and how to calculate built-up area from plot area shows how much you can build. For sample layouts, see these 2 BHK house plans. Our architecture team prepares sanction and working drawings for homes and commercial buildings.
FAQs
What is a building plan?
It is a set of drawings that shows how a construction project is designed and how it should be built: where the building sits on the plot, the layout of each floor, the structure and the services.
What does a building plan contain?
It contains the site plan, the floor plans, the structural plan and the services plan covering water supply, drainage, electricity and gas. Larger projects also include a landscape plan for the open areas.
Can you alter the building plan after it has been approved?
Minor changes are generally allowed. Any significant alteration needs the revised plan to be approved again and may cost extra money, so it is better to settle the design fully before applying.
Who prepares a building plan?
An architect prepares the site plan, floor plans and elevations. A structural engineer prepares the structural plan, and the services drawings are prepared by engineers or technicians for electrical and plumbing work. Software can help you sketch ideas, but the final drawings should come from professionals.
Is building plan approval required before construction?
Yes. The plan has to be submitted to the local authority and approved under the zoning and building rules for the area before work starts. Building without a sanctioned plan, or differently from it, can lead to penalties or demolition orders.
