If you're planning on developing land and seeking planning permission for your new project, don't forget to find out if there are any heritage assets at the site.

And the sooner the better.

Under Planning Policy Statement 5: Planning for the Historic Environment (PPS5)* all applicants are required to assess the significance of heritage assets. Dealing with them to the satisfaction of the local planning authority can be costly, both in terms of money and time.

Although historic buildings or monuments on your site may be obvious, the definition of 'heritage assets' includes any 'site, place or landscape which is positively identified as having a degree of significance meriting consideration in planning decisions'. It's very easy to overlook these assets, particularly if they have archaeological significance and are hidden underground.

Public records will provide an understanding of the history of your site but if necessary, expert advice can be sought, says Catherine. If it turns out that there's an archaeological interest, a local authority will need a full report on the available published data and possibly a small excavation of the site - both of which would need to be commissioned from a professional archaeologist.

It's rare that heritage assets are considered too important to allow a development to proceed but planning permission might come with certain conditions relating to specific assets.

Where the potential for significant archaeology has been identified, these conditions could range from a watching brief by the archaeologist to a full-scale site excavation. In all cases the work would require a published report.

Costs for each phase of dealing with heritage assets need to be factored in to a project.

Conditional contracts or option agreements can be drafted to include provisions allowing the purchaser to have access to the land to carry out a field evaluation in addition to the usual soil, water and environmental tests.

The results of such an evaluation could then be taken into account in assessing market value. The significance of heritage assets, particularly archaeological remains, won't always be ascertainable before excavation and it may be appropriate to allow for additional indemnity provisions, possibly backed by a retention, 'an escrow' account or another form of security.

• The author can be contacted on 01227 763939 or email cw@furleypage.co.uk More details at www.furleypage.co.uk