Check the licences, accreditation and credentials of the firms they have hired.
Request quotations from more than one design firm.
Discuss proposed designs and project schedules with the designer.
Vet thoroughly not only the colour schemes, but also the materials to be used and the dimensions.
Note the capabilities of the contractor engaged by the interior designers to execute the proposed designs.
Check that the contract lists the products and services and that the bill is itemised.
Set up a schedule with clear deadlines.
Set up a progressive payment schedule. Payment should not be made in full upfront.
Document and take photos of outstanding defects in case of disputes.
Refer to the list of accredited CaseTrust contractors available at www.casetrust.org.sg
Use a model agreement on home renovation, which can be found at www.case.org.sg/model_agreements.html
Refer to the Building and Construction Authority's guides on good industry practices. The website can be found at www.bca.gov.sg/Publications/EnhancementSeries/enhancement_series.html
Seek the assistance of Case or file a claim with the Small Claims Tribunal if a dispute is unresolved.