LONDON—British house price growth accelerated in January, marking the strongest start to any year since 2005, mortgage lender Nationwide said on Tuesday. House prices jumped by 0.8 percent in January, following a 1.1 percent increase in December. A Reuters poll of economists had pointed to a 0.6 percent increase last month. House prices stood 11.2 percent higher than their level in January 2021, the fastest annual growth since June and again outstripping the consensus forecast for a rise of 10.8 percent. Other surveys have also pointed to strong house price growth, even after the expiry of temporary tax breaks on property purchases during the pandemic. As in other countries, British house prices surged during the pandemic as people rushed to move to bigger homes with gardens. Nationwide said demand was likely to cool this year. “Reduced affordability is likely to exert a dampening impact on market activity and house price …