One of the major delays when buying a house are the local searches that your solicitor will insist on performing. Some houses and locations will require more searches than others. The searches are to ensure there are no nasty surprises that could ruin your home and to some extent protect the mortgage lender's investment too.
Your solicitor will decide which searches are needed but here are a run down of some of the main ones:
The Land Registry search is performed to check that there are any unknown mortgages registered on the property. This is obviously to check that the house is the seller's entire right to sell. If there are other mortgages on the property the solicitor will need to confirm that they will be repaid before the sale.
The conveyancing solicitor will do this search to check that you are not bankrupt. This is done for your mortgage lender since they will of course want to check that you are not completely unstable financially and that their huge mortgage lend to you is a sensible one.
Your new home will registered with a Local Authority or council. Your solicitor will check with this council to find out if there is anything current or planned that could affect your property's value. This will only include things that the Local Authority is currently aware of such as if a main road is planned very close by or if a new train line is planned to run through your house. It could also be outstanding issues with your actual property such as an unauthorised extension or tree preservation orders. It will not include neighbouring houses' private planned developments.
Your solicitor may perform this search if it is likely to be a problem for your area. It will be performed to see if your property has been built in an area with risk of subsidence or flooding or if it is built on a previous industrial site which could spell contamination risks. There will also be checks for local landfill and waste disposal sites.
There will be a check to see where the drains from the house run. The check is to see where foul water drains and surface water runs and if their destination sewer is private or publicly owned.
If the house is being purchased in part by a mortgage, the lender can require that your solicitor do various searches on their behalf too. One if often doing a bankruptcy search against the purchaser.
So it turns out when your solicitor tells you they are still waiting on some searches to come back they are not just fobbing you off, there genuinely is a lot to do and it can take a while. Personally, I find the Local Authority search to always be the last to come back but all searched tend to be done simultaneously so although there are a lot to do it tends to only take as long as the longest one, which is usually the Local Authority search.