Architectural specifications are a crucial part of the architectural design process. They provide a detailed description of the materials, products, systems, and techniques to be used in the construction of a building, and serve as a guide for contractors and subcontractors during the construction phase.
- Detailed description of the process of all workmanship and materials which are required to complete a building or project in accordance with its drawings and details.
- The data regarding the materials and workmanship is conveyed in a separate contract document known as the “Specification” for the work.
- Best example to understand the specification is, making Tea.
- There are different steps in making tea.
- Collecting ingredients
- Method and right quantity of all ingredients.
- If any of the ingredients vary from there quantity, tea losses its taste & looks.
- Similarly Specification in construction tell about quantity of the material & method of the preparation of the material like RCC, casting slab, about excavation, masonry work etc.
2) Need of specifications
- Support for our drawings
- Agreement between client and architect
- Providing solution to challenges
- The cost of an unit quantity of work is governed by its specification.
- Specification of a work are required to describe the quality & quantity of different materials required for a construction work and is one of the essential contract documents.
- This also specifies the workmanship and the method of doing the work.
- A work is carried out according to its specification and the contractor is paid for the same.
- As the rate of a work is based on specification, a contractor can calculate the rates of various items of works in a tender with his procurement rates of the material & labour.
- Specification is necessary to specify the equipment’s, tools & plants to be engaged for a work and thus enables to procure them before hand.
- The necessity of specification is to verify and check the strength of material for a work involved in a project.
- Specification is an essential contract document and is required for arbitrator or court cases.
- A structure, such as a wall, built of bricks
- Providing and doing 230 mm thick brickwork in first class brick in 12mm thick mortar 1:5 (1 cement : 5 – badarpur sand) in English bond in straight or curved profile at all levels in perfect alignment, level and plumb to the entire satisfaction of engineer in-charge.
- The brickwork shall be cured for 7 days with portable water.
3) Good specifications
i) Time management
- Each stage of Project proceeds smoothly.
- Procuring and organising materials and labour ensures proper Time Management of the Work
ii) Quality control
- Specifications written with clarity about the materials and the process of workmanship have better control on the Quality of work
iii) Minimal litigations
- Clarity and accuracy on description of work and procedure of carrying out works will avoid and confusion and litigation
iv) Financial planning
- Clarity and specific instructions help in working out accurate pricing/ cost of the items of works of the Project
4) Types of specifications
i) Brief Specifications
- Brief specification gives the nature and class of work and materials in general terms to be used in the various parts of the work.
- It is a short description of different parts of the work specifying materials, proportions, qualities etc.
- General specifications give general idea of the whole work or structure and are useful for preparing the estimate.
- These general specifications do not form part of the contract document.
General specifications of some works involved in the construction of a residential building
- Foundation Concrete: Cement concrete 1:4:8 using 40 mm size blue granite broken stone.
- Foundation and Basement: Brickwork in cement mortar 1:5 using first class bricks.
- Super Structure: Brickwork in cement mortar 1:6 using first class bricks.
ii) detailed specification
- The detailed specification of an item of work specifies the qualities and quantities of materials, the proportion of mortar, workmanship, the method of preparation and execution and the method of measurement.
- The detailed specifications of different items of work are prepared separately which describe what the work should be and how they should be executed and constructed.
- Detailed specifications are written to express the requirements clearly in concise form avoiding repetition and ambiguity.
- The detailed specifications are arranged as for as possible in the same sequence or order as the work is carried out.
- The detailed specifications form a part of the contract document.
iii) Standard specifications
- Standard specifications are those which remain same for various types of projects.
- Different public sector organizations collect data from various types of construction work and published data in the form of a book. (CPWD Specifications)
iv) Special specifications
- Sometime construction projects are of special type.
- Specifications for these types of projects are not mentioned in detailed specifications book. Consultant has to write specifications for this type of work
5) Essential Requirements of good Specification writing
i) Subject matter
- The subject matter of specifications should relate to the information required after the contract is given to a particular contractor. The requirements which are to be enforced should only be included in the specifications.
- All sentences of the specifications should comply with the rules of grammar. The style and tense should remain the same throughout.
iii) Selection of words
- While writing specifications, only suitable words with desired meaning should be used. Unfamiliar words or words having more than one meaning should never be used in the specifications.
- The information given in the specifications should be complete and correct.
v) Practical limits and commercial sizes
- The specifications should be framed keeping in view the practical limitations of materials and workmanship and they should not specify practical impossibilities.
- The specifications should be fair and they should not be framed in such a way as to throw all the risks on the shoulders of the contractor.
- The sentences of the specifications should be short, simple and concise.
6) Points to be Included in the Specifications
The specifications shall contain the following points:
- Quality of materials to be used with strength/size requirements,
- Quantity of materials to be used and the methods of measurements to be followed.
- Method of mixing when different materials are used.
- Construction methods to be followed mentioning the equipment and machinery to be used.
- Dimensions of works such as breadth, thickness etc.,
- Methods of measurements of works for payments.
7) Detailed specification of for brickwork in cement mortar 1: using first class bricks in super structure
- Bricks shall be table molded, well burnt in approved kiln, copper coloured, free from cracks and with sharp and square edges. Bricks shall be uniform in shape and shall be of standard size and shall give clear ringing sound when struck with each other.
- Bricks shall be well soaked in water for at least 12 hours before their use, preferably in a tank provided at site of work.
- The proportion of mortar shall be one part of cement to five parts of sand by volume and shall be prepared as per standard specification for cement mortar. The cement and sand shall confirm to the standard specification.
- Broken bricks shall not be used except as closers. All corners shall be truly to plumb. Mortar joints shall break for bonding and shall not exceed 10 mm in thickness. Only skilled masons shall be employed on the work and the work shall be kept well-watered for at least 15 days. All brickwork shall be carried out in such a way that no portion is raised unduly above another.
- The length and height shall be measured as on site. The thickness of walls shall be paid for as one brick, one and a half bricks, two bricks and so on. The rate for brickwork includes necessary scaffolding also.
If you want to know about the specification on earthwork in excavation or specification on brickwork and concrete or specification on carriage and stacking of material, please click the link.
These specifications help ensure that the building is constructed according to the design intent and meets the necessary building codes and regulations. They are an essential tool for ensuring the quality and safety of the building, and serve as a reference for resolving disputes that may arise during the construction process.