"A bit of basic home maintenance and some re-jigging of the wiring in the living room could speed up internet connections no end," said TalkTalk engineer Dan Downham.
Some customers may be experiencing speeds up to four megabits-per-second slower than expected because of problems between their phone line and their computer. The average speed of a broadband connection in the UK is 7.6Mbps.
The most common problems within the home included faulty wiring, which affected almost a third of homes visited by engineers, and poorly configured routers, which accounted for a further fifth of home visits.
These problems could prevent common internet applications such as the BBC iPlayer - which requires 3.2Mbps to deliver HD video - from functioning correctly or at all.
Even forgetting to install ADSL filters or not connecting the ADSL modem or router directly to the master phone socket could have a significant impact on speeds, TalkTalk said.
"People need to think of broadband in the same way as water and electricity," said Mr Downham. "It's a commodity that can go to waste if you're not careful."